Kennen Build Guide by WoopeyWoo
Not Updated For Current Season
This guide has not yet been updated for the current season. Please keep this in mind while reading. You can see the most recently updated guides on the browse guides page.
Mid Lane Kennen is F✯✯king
First Back Goals
Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
The point of this guide is to be a resource that goes in-depth on each segment of what you'd like to know for Kennen in an attempt to help develop solid play through the many scenarios that can take place within League of Legends. I plan to go over the masteries, runes skills, builds, matchups, game phases, and tips I've learned while playing Kennen all this time.
Kennen has always been a relatively safe laner with his ability to farm at long distance with Thundering Shuriken (his Q skill), his great sustain with a Hextech Revolver and spammability due to his energy resource as opposed to the usual mana one on most champions. No matter how badly you get denied as him, he will always have his usefulness as an AoE CC bot due to his ultimate and opponents won't be able to cut it short once you get Zhonya's Hourglass. He fills the much sought-after AP top niche when you have an AD mid and jungle, and does it well at that with his amazing teamfight. Kennen has, in my opinion, the most fun playstyle of any champion so far with his passive. The marks give him a combo-esque feel and allows for amazing plays when you really keep track of them. All in all, Kennen is a really fun champion who remains strong, and those who take the time to learn him will like the results.
Safe laner if built for such
- Has good mobility
- Great teamfight
- Good lane harass with his W (Electrical Surge), especially against melees
- Energy resource is fantastic for laning
- Capable of doing well in multiple roles
- A lot of fun to play
- Has to be in the middle of the opposition for maximum effectiveness
- Exhaust really screws him over in teamfights
- Not as good as most other APs when his ultimate is on cooldown
- Can be Flash reliant
- Is hurt badly by magic resist and health
- Wave clear generally relies on being ahead of opponent
- Can't stand pressure from those he can't kite
Shuriken - Thundering Shuriken (Kennen's Q skill)
Surge - Electrical Surge (Kennen's W skill)
Rush - Lightning Rush (Kennen's E skill)
Maelstrom - Slicing Maelstrom (Kennen's R skill)
Energy - Resource for skills used by Kennen. Stays at a max of 200 and constantly refills by 10 every second.
At level 1 you're usually going to start with Electrical Surge for the great damage the passive and active together will do to a target at that level. Typically try to go for Lightning Rush next so you can escape from or setup ganks that commonly happen at level 2. If you don't have an escape when the opposing jungler comes to your lane, chances are you're going to have to blow Flash, which will put you at a large disadvantage that early on. If your jungler comes to your lane, you want to make sure you can reach your opponent so you can actually help with the gank, possibly leading to a kill or a free blown Flash.
In terms of what to max first, Kennen commonly switches skill order between different matchups. You will generally focus on either Thundering Shuriken or Electrical Surge, while putting points into his ultimate whenever possible. Try to avoid alternating between the two, so you can abuse the low cooldown on the higher up one to set up more marks and damage on a target without having to rely on hitting two abilities. In top lane, I max Electrical Surge a large majority of the time, since it allows you to zone melees with little effort and keep constant marks on them. In lanes where you just seek to farm, or plan to go Hextech Revolver for lane sustain, max Thundering Shuriken first so you can farm from a distance and be near impossible to move from lane as a result. Keep in mind this closes the harass options brought up by maxing Electrical Surge first, and you won't land much harass against a laner that hides behind minions. You won't be the strongest pusher either, but it's a reasonable trade for becoming a near unmovable lane presence.
In terms of Lightning Rush there are times when this can be leveled earlier than the others, and sometimes even maxed first, though this is very situational. When you are going against a melee champion that is giving you a lot of trouble whenever they manage to catch you, leveling Lightning Rush earlier will give you more armor and magic resist to deal with it while also dealing damage with its high base. If you're going to level this early go for a Haunting Guise and not Hextech Revolver since you won't be able to take full advantage of the spellvamp while also getting the most out the base damage with the spellpen on Haunting Guise. If you're going against a melee and are winning, max Thundering Shuriken or Electrical Surge first and then you can max this second to make it very difficult for the opponent to kill you when they do manage to reach you.
Basically, max Electrical Surge for lanes in which you plan to be aggressive and max Thundering Shuriken for lanes where you just want to sustain and farm. Start Surge regardless in most lanes followed by Lightning Rush at level 2 to help with ganks. Max what helps with the matchup once you have all one rank in all 3 abilities.
Choose your starting items and prepare yourself for your matchup. Early game in midlane consists of farming up to at least get the levels for your abilities while harassing as the opportunity arises. Keep at least one side of the river warded and lean towards it if you plan to be aggressive, just make sure you don't miss those last hits. This way if the enemy jungler pops up on the side your on, you'll see it ahead of time and if he appears out of the unwarded side you'll have vision of a safe escape route. Try your best to get to level 6 as that's when your kill potential really opens up on most matchups, so focus on that above all else. Help your jungler if they're being bullied in their jungle, as early on this happens quite commonly. Other than that, there isn't really much special about early game midlane on Kennen.
This is where midlane starts to get serious. Midgame midlane is where you should try to start making plays happen around the map. Dragon opens up as a big early objective and you should try to think of ways in which you can secure it for your team. You can roam to bottomlane, catch their jungler, or kill your mid opponent to open it up if your team is healthy enough. I would advice against roaming top at this point in the game unless you plan to take the tower or else the enemy could retaliate for you showing by taking dragon for themselves, which will be worthwhile for them even with a kill if you don't get the tower.
Keep in mind ranks of your ult when you force fights around the map. With only 1 rank in it, Maelstrom will only be able to put out 6 bolts onto enemies, and they're applied randomly to champions within it. Without being able to stun your targets this early on you really need to be careful about what you jump into. You also most likely won't be that tanky shortly after getting your ult, so you really do need to choose your fights wisely.
It is also important to keep mind of your jungler's location. It is also important for midlaners to help their junglers if they're in sticky situations or warn them if your lane disappears. If you and your jungler help each other out you'll gain a good amount of control over the map as you both are the roles with the most impact on the map. You can also follow them if they decide to gank, which will increase chances of success and the money pool your team receives from the kills you may get as a result of more assists.
Always keep in the map in mid when it comes to midgame as Kennen and really think about roaming once you hit level 11. With 2 ranks in your ult you'll be able to fight in larger groups with more success and you should also have at least one core item to help you lead them in the direction you want. Remember, winning your lane isn't always enough to win the game. You have to be in the middle of the result of your other lanes, so it's best to not only reduce the threat of your own opponent but all of them in order to maximize success.
Summoner Spells Explained
Let's be real, Flash is a given on most, as it helps with escaping, initiating, dodging, and so much more. On Kennen specifically it's vital, as having Flash up gives you such a huge boost on your ability to position or initiate with your ultimate in teamfights. Flashing onto a squishy and continuing your combo on them will almost always lead to their death with no way for them to retaliate. No matter what the scenario, YOU WANT TO HAVE Flash.
This gives a lot of kill potential in lane. With it you can be more lenient with your all-ins, as you don't need to finish them off yourself or have to worry about them flashing away if you hit them with Ignite as they're about to die. It also halves healing which helps in killing heavy lifesteal or spellvamp targets. This is usually the second summoner I take when I play Kennen.
Though uncommon on him, Teleport allows for many big plays and opens up pushing options when they matter most lategame. Post-6 when you have your ult it opens up large ganking possibilities into the other lanes, whether you're top or mid. Ganking bottom lane from behind using Teleport and killing off the opposing bot lane is huge, especially if it nets you a dragon for your efforts. it also lets you go back to lane and barely miss out on CS if you're forced back for whatever reason. Lategame it allows for you to push back lanes while still being available to your team if a fight breaks out. Very underrated summoner spell, I rarely take it as well, but it's good.
This has been seen on a lot of mids as of late, as it can be used for baits or surviving close-call situations. I can see how it'll have it's uses, but remember, even though Barrier has higher numbers than Ignite, it only lasts for 2 seconds as opposed to the 5 on Ignite. This means it'll only shield less than half of the damage, so don't rely on it to survive if the Ignite ticks are about to kill you. In teamfights, Barrier should absorb the numbered damage as you should be taking more damage than that when you go in, so it has its uses when your in the middle of the action. It's more of a defensive summoner than an offensive one, which goes against my playstyle so I don't run it at all. Even then, it's still good on Kennen.
Mark of the Storm
Enemies hit by Kennen's spells receive one Mark of the Storm, which lasts for 6 seconds. These marks stack and upon receiving 3 Mark of the Storm, they detonate to stun the target for 1 second and grant Kennen 25 energy. If the stun is applied more than once within 7 seconds, it has a diminished effect so it will only stun for approximately 0.5 seconds.
This passive is what makes Kennen such a fun champion for me. The mark and returns system allows for some serious combos that often catch opponent off guard, since you can setup what you want to do with them in advance. By successfully landing 3 marks on a target, they are stunned and a bit of your energy is refunded, as stated in the skill definition. Since Kennen will run out of energy if you spam constantly it's important that you make sure you actually get the stuns off on a target in order to fuel your harass. Be sure to always monitor how much marks you have on a target and plan plays ahead of time in order to make the most of this passive. As of Patch 3.9 mark management is of even more vital importance due to the duration being reduced to 6 seconds.
Kennen throws a charged shuriken in a line in front of him, dealing 75/115/155/195/235 (+ 75% AP) magic damage and applying a Mark of the Storm to the first enemy that it hits.
This skill is one of the two main skills you need to pay attention to as Kennen. It functions as a single-target nuke with good base and a good ratio that also applies a mark of your passive on hit. This is your safe-farming tool with its great 1050 range and it also works extremely well with spellvamp, along with the fact that it's spammable, to keep you healthy in lane if maxed first. If you manage to land one on an opposing champion, it'll chunk them a good amount and will apply the vital first mark needed for the combo without expending the longer cooldown Electrical Surge and from a safe distance. Be warned though, it can be very difficult to land one of these against a smart player as they can just stand safely behind minions, so it isn't a first max in all situations, despite its benefits.
Since this move is a skillshot that stops when it hits, it can be used to check brushes when you have no vision in them. You'll see the animation stop and hear the noise from when it strikes a target, so if you're ever worried about face-checking a brush don't be afraid to throw one of these in ahead of you to confirm whether or not it's safe.
PASSIVE: Every fifth basic attack will deal 40%/50%/60%/70%/80% of your total AD in magic damage and add a Mark of the Storm to his target.
ACTIVE: Sends a surge of electricity through all nearby enemies afflicted by Mark of the Storm, dealing 65/95/125/155/185 (+ 55% AP) magic damage and adding another Mark.
Now this is the other skill which needs to be watched when playing Kennen, even more so than Thundering Shuriken. Starting with the passive, which is an auto attack enhancement that adds additional damage and applies a mark when it strikes a target. This helps a lot with adding the oh-so-important first mark on a target, which sets you up for a combo with your other abilities. Try to land this on champions whenever it gets up but don't miss out on CS trying to hold onto it. Moving onto the active, it's unique among Kennen's abilities in the way that it can only be used once a mark is already on a target or targets. It will hit anyone with a mark within 800 range of Kennen, which is still pretty far. This skill allows you to push a lot easier and harass melees almost effortlessly by hitting them with its passive followed by the active. In teamfights it adds damage onto everyone marked by your ult, and will make sure they will have at least one mark still on them after they've been hit with each bolt, which also brings out more AoE damage than maxing Thundering Shuriken in fights with more than one person. Most of the time I max this first, as it allows you to push more effectively and opens up new harass options. What I mean by that is that when the skill is ranked to 5, the cooldown becomes 6 seconds which means with the 4% CDR from the mastery you can use it more than once on a target before their mark runs off with proper timing. It's due to the new easy harass options and ability to push lanes back that I max this first in most matchups.
It's worth noting that if you use the active on Surge right as a mark runs off a target Kennen will still jump like he used the skill but it won't actually go through, but the it'll take the energy away regardless and it'll be on cooldown. Watch out for this.
Kennen transforms into a ball of electricity for up for 3 seconds. While in this state Kennen gains 230 movement speed and ignores unit collisions. Any enemies he passes through take 85/125 /165/205/245 (+ 60% AP) magic damage and have a Mark of the Storm applied to them, dealing half damage to minions. Kennen also gains 40 energy from the first enemy he hits. Kennen cannot use basic attacks while Lightning Rush is active. Additionally, for 4 seconds Kennen's armor and magic resistance are increased by 10/20/30/40/50. While Lightning Rush is active, Kennen can activate it again to cancel the first part of the ability.
This is your chase and escape skill with a high cost attached to it. It has the highest energy cost of all your abilities but gains a small refund of 40 energy when a target is hit. Keep in mind though, this only applies with the first enemy hit so hitting two minions with the skill will still only refund 40 energy. When you want to clear a wave it is smart to Lightning Rush over the minion wave followed by Electrical Surge to bring the wave to a reasonably low amount of health with some AP. However, this method leaves you open to ganks and retaliation from your laner, so do not do this freely unless you know that you're safe to do so. The damage on this ability is often overlooked as well, dealing solidly more damage than Surge at all levels with a higher ratio to boot. If you are ever attempting an all in try to hit them with this ability at some point for the extra mark and damage, but don't go out of your way and get yourself killed trying. I'll say it again since it deserves emphasis, make sure you don't use this skill for harass or waveclear unless you know the jungler isn't in the area or you'll be very vulnerable for a great gank by the opposition.
Don't forget about the bonus armor and magic resist as well. It can really help you get through otherwise fatal situations, though you can't auto attack while Lightning Rush is active. To work around this, you can cancel Lightning Rush in the middle of the active early and still receive the armor and magic resist for the full duration of what would've been the active. So be sure to cancel Lightning Rush as soon as you've used it for whatever you planned so you can auto attack again while keeping the bonus resistances.
Kennen summons a magical storm around himself that zaps a random enemy champion within range every 0.5/0.4/0.33 seconds, dealing 80/145/210 (+ 40% AP) magic damage per bolt, for a total of 240/435/630
(+ 120% AP) on each target struck by 3 bolts and applying a Mark of the Storm for each hit. The storm hits 6/10/15 times, and cannot hit the same target more than 3 times.
This skill may not require as much attention as Thundering Shuriken or Electrical Surge, but it is the biggest skill in Kennen's kit. This is what makes my favorite champ so good at teamfights, and is his shining point in them. Using this correctly can be the difference between a good engage or a bad one, as it allows you to lockdown a target, do high damage to them while damaging anyone else near, and refunds energy from all the marks of the passive being set off on those within it. In lane it can be used to setup a triple stun on a single-target with only 1 point in it. When maxed it can stun everyone caught within it on its own, which makes it difficult for others to stop you from destroying your target while simultaneously eating damage from the rest of your team. Combined with the invulnerability on Zhonya's Hourglass, the opposing side is going to have to think of a way to deal with you alone ahead of time. Make sure that this up before fights if possible.
An important overlooked part of this ultimate is the amount of bolts and how it increases per level. The bolts don't do much damage on their own, just the total of all of them together is what causes the real damage. Because of this, you should try avoiding fights with 3 or more people while it's level 1, as chances are you won't have any big items yet so you can't afford to be in the middle of 3 people with your ult not stunning even one of them. The bolts will be spread out among the group, doing little damage and not stunning them on its own, so always take the ult level into consideration before hard-engaging with it.
Choice Of Boots
Boot choicesOR OR
These are the 3 main choices of boots on Kennen
These are generally what you're going to go with on Kennen. The flat magic penetration is really useful early-midgame and adds a good amount of damage to your harass and burst.
This choice is effective in counteracting champions reliant on some sort of CC or silence to keep you at bay or champions with high magic damage burst. Some examples are LeBlanc, Kassadin and Veigar. It'll give you some very nice early magic resist and what will most likely be the only tenacity you'll get out of your build. Get these if you are going against tough magic damage dealers or CC reliant champions to reduce their effectiveness against you.
These have always been pretty effective in handling heavy physical damage champions or those who rely on auto attacks to take you down. Some examples are Riven, Tryndamere and Fiora. Their damage output will be severely reduced with this cheap buy and it should help you if you're having trouble. Get these if you want to take less damage from heavy auto attackers or physical damage dealing champs that give you trouble. More commonly built in toplane than midlane.
In terms of Boot Enchanments
Enchantment: Homeguard OR Enchantment: Distortion
Enchantment: Homeguard Is extremely helpful in any situation where you need to defend the base or just for getting back to lane quickly whereas Enchantment: Distortion will bring up your Flash and Ghost if you're running it, which is big in teamfights, more quickly and Teleport, which will have a big impact all points of the game. Either way, get these when you feel they are necessary as there isn't really any particular point in the game where you need them.
Start Of The Game
5xSight Ward OR
2xSight Ward OR
Keep in mind, these are not the definite starting options, just the most general and they work against pretty much every matchup.
If you want specifics for a lane just check out the "Matchups" section below. After Patch 3.6 this section required some mass revisions. Both of these two new choices may seem outlandish but bear with me. So first off I'll explain the 5 Health Potion, 1 Sight ward, and 1 Vision Ward start, which gives the maximum amount of Health Potion, wards to avoid early ganks, and a pink to deny some early vision from your opponent. This start gives you more than enough wards to ensure safety and opens up the possibility of setting up ganks by ridding of your oppositions ward(s). You'll have some leftover money but just save it as a bonus for your next back since there really isn't much more use for it this path. The Boots of Speed, 2 Health Potion, 1 sight ward start became good after they reduced the amount of gold Boots cost, allowing for more than 1 potion. Last but not least is the Cloth Armor, 2 Health Potion and 1 Sight ward start. This seems to be the best start against ADs in my opinion as long as you don't eat too much return harass. If you have trouble taking too much damage back but aren't afraid of the burst just go the potion route instead. If you don't need to help the jungler with wraiths or wolves you can wait 5 more gold for a 3rd pot on this start.
Due to an extreme amount of questions brought up by Ambition's play in LCS I thought I'd throws this in. Doran's Blade start can be really effective if you're confident that the opposing jungler won't gank early on when you don't have wards or the opposing laner is weak early with little-to-no CC. People that commonly start Doran's Blade toplane assume the jungler is going to start the buff closest to their side, meaning that the jungler will head towards the opposite side of the map before coming to their lane to get their other buff, giving them as a laner enough time to utilize Doran's harass before heading back for a ward. Even if you are willing to take that chance you need to be sure that the opposing laner won't be able to return a lot of harass. Most everyone starts with some potions so if they hit you enough you'll be behind in health and won't be able to utilize the harass from Doran's due to the HP difference. Maybe against someone like Singed or someone who can't reach you, but other than that I don't like it as a starting item.
Tips And Tricks!
Constant Marks; Very Important for Laning!
As you most likely know by now, Kennen's mark system works on a system that allows him to setup stuns in a combo-esque fashion. Due to the fact that your Electrical Surge can only hit enemies already marked with your passive, you need to usually go out of your way to get a first mark to setup a stun. However, if you take advantage of each downtime on an opponent while stunned you can apply another first mark to start another rotation. This means you actually need to be mindful of your cooldowns however, as you shouldn't be spamming your abilities just because they're up. Try to time your stuns in a situation that sets up a hit with a Shuriken or Electrical Surge passive to keep marks going, allowing for a long chain of harass that'll require the enemy to back up to end. Let's say you stun someone with Surge, you should then, while they're stunned, position yourself to hit them with a Shuriken, which would be simple since the opponent can't move. This will give you 8 seconds to get up your Electrical Surge passive, which should then be used to reset the mark time and add another. Follow it up with Electrical Surge which should be off cooldown by now and throw another Shuriken while they're stunned. Starting to see the chain? This will also refund 40 Energy on each stun, allowing for the combo to constantly be used over and over until the the marks run off by whatever means. As of Patch 3.9 this is more important than ever.
A Couple of Stun Setups
Melee-peel combo: Rush an enemy that is in melee range followed by a Surge active and a Shuriken to stun them in place while Rush is still active to regain your distance. If they had a mark on them beforehand you can just Rush and Surge to auto-hit the opponent with a Shuriken while they're stunned and you're running.
All-in setup: Try to get two marks on the enemy beforehand, however you please to do so. Get your Surge passive up, wait for your cooldowns to refresh and approach the enemy with Rush, Surging them on the way to stun them. Activate your ult, throw a Shuriken at them and pass through them with Rush to stun them again where they stand. Deactivate Rush, throw the passive and let your ult strike them twice more to stun them a third time on the spot. If this is executed well you will have pretty much maximized your burst on a single target and stunned them 3 times in a row. This feels amazing to pull of correctly.
There is much more you can do, but these are two of the setups you should be using commonly. Have fun finding out more for different situations as you learn him!
Roaming as Kennen
I thought I'd add this little tidbit after watching a friend of mine attempt to roam as Kennen. When roaming you can use Rush to help you reach the lane that you plan to gank, but MAKE SURE YOU HAVE IT UP WHEN YOU GET THERE. Most enemies aren't going to let you just walk up to them and burst them down, you're going to need a way to close the gap. Even when you have Flash up, use it to land on top of them with Rush to maximize your damage and lockdown. Regardless of where you're going ask where wards are located, avoiding wasting your time if they don't know or if everything is warded. I recommend going bottom lane over toplane a majority of the time as when you go toplane there is only one target, and he tends to be harder to pick off since toplanes tend to build more tanky. You can also lose dragon as their will be four opponents near it whereas you'll be away from it up top. Down bottom lane there are two squishy targets that open up dragon potential if picked off. You should generally prioritize them, and chances are the opposing mid will do the same.
Always be mindful of where the opposing mid is at when you roam, by the way, as they can counter-gank, potentially turning the situation around in the opponents favor. You can also arrange to have your jungler head down to join in, but so can the opponent. Watching the map is key when you plan to roam as you may end up fighting a 3v3 or even a 3v4.
Farming Under Tower
Kennen is a champion that has trouble against early pressure as his pushing ability early on in the game is pretty pathetic. To compensate for this, I thought it might be important to add this, even if some of it applies to champions besides Kennen. When under tower you have 3 types of minions to worry about early on, Fighters (melee), Casters (ranged), and Siege (cannon-riders). Each has a different way of successfully being last-hit under tower.
Fighter minions - From full health let them take two tower shots before auto-attacking them and this should snag you the last hit. If they already have taken a bit of damage try your best to get them to near half before the first tower shot and hit them one more time afterwards for the last hit.
Caster minions - From full health these need to be auto attacked twice along with one tower shot to successfully pick up. Generally you'll auto attack them once, have the tower hit them, and auto attack again to get them. However, on Kennen what I usually do is use Lightning Rush over the full-health Caster minions and cancel it immediately after I've hit them all. This leaves them at a point where only one auto attack is needed to finish them after a tower shot. If they have about 80% health or less when they reach the tower it'll take them out in one shot, so try to get those ones before they're targeted by the tower.
Siege minions - The cannon-riding minions usually don't have as much of a pattern to them due to the amount of turret hits they can take. You must make sure you get them though, as they are worth the most gold and give most experience for being near. Watch their health drop between tower shots while keeping in mind that towers do more damage per hit and go for the last hit when they can't take another tower shot. You can attack them a bit beforehand to speed up the process so your tower doesn't take as much damage.
Safely Rushing to WaveClear
When in lane there are times that come up when you want to Rush and Surge the wave to clear it but don't quite know it's safe. What I commonly do when the opponent is missing walk up to the back of the minion wave and Rush back towards safety, so that if the enemy were to have been waiting for you to burn it you'll already be using it as an escape instead of having it be down midway through the wave.
Lategame Kennen/ TeamFighting
At this point in the game what lane you were doesn't really matter as it's the time where your team starts coordinating to take objectives as a group. Though Dragon is still nice, Baron opens up as the new primary-monster objective with its capability to turn games or make a lead even larger. As a strong teamfighter you need to make sure you stick with your team as much as possible to make the best use of your strengths. Both teams should be looking to get a good engage or catch an opponent out of position to make use of the long respawn timers at this point in the game to push down towers and objectives.
In terms of pushing, Kennen is a relatively snowball-y sieger and defender. If you're ahead you can manage to get close to auto attack towers and Rush over minions followed by Surge when defending them. If you're behind it becomes difficult to do either of these. People won't be scared to stop you from autoing their tower if you aren't a large threat, and people definitely won't let you Surge over their minions for free if you try to while defending. Always be mindful of how strong you are during pushes from either team during lategame.
It goes without saying that teamfights are important, and as Kennen you should be making sure you play them out correctly. You need to identify threats to your team and take them out in accordance to priority. You also shouldn't be initiating unless you have no one else who can, instead letting your more tanky teammates go in first so you don't eat everyone's initial burst. You should be playing one of two roles in a teamfight depending on situation, and this should be decided usually before the fight breaks out. You need to always be mindful of cooldowns when these break out, especially Exhaust and Cleanse.
More commonly you'll find your teamfight role to revolve around being a carry-killer, trying your best to rush the opposing sides squishy damage dealers in order to wipe them out of the fight before they can get off their damage. This is usually really easy to do with Flash, but becomes more complicated when it's on cooldown. When Flash is up you should look for an opening once the abilities that can hinder your ult are on cooldown and attempt to Flash onto your target with Rush active, for the mark and damage, and activate your Maelstrom. If you manage to do this and hit with Surge they'll be stunned the second you reach them, making landing a Shuriken easy readying them to be stunned again. Most targets should not be able to survive this chain of events if all goes well. However, without Flash you'll have to try to Rush yourself into range to get targets locked into your ultimate, which means you're going to have to run through the opposing frontline. Make sure the enemy doesn't have any knockbacks or CC to stop you from reaching your target when you do this as you'll lose your biggest opportunity and will be left out in the open with no Lightning Rush.
The other role you can take on in fights is the peeler, which should only be done if you're really behind and your squishy damage dealers are big. Basically in this role you hug your sqhishies and chain-stun anyone who dares to get near them, setting up your damage dealer to kill them while lowering them yourself in the process. This will really help against the opposing rushers and leave the opposing squishies open if you kill them fast enough. Remember, this should only really be done if you're behind so don't be afraid to jump in front of your carry to take skillshots and whatnot if you think it'll save them at this point.
Always be mindful of how you use your Zhonya's Hourglass if you have one, regardless of which role you take. Jumping in and instantly using the Zhonya's active isn't usually the best idea, as it allows for the opposition to split up or run out of it while you can't move. Instead you should use the active when you start getting targeted, saving you from eating what could be lots of damage. It's ultimately up to you to use it when you see fit, but I'm just saying think twice about instantly using Zhonya's once a teamfight breaks out and instead consider using it for other purposes.
Though you should attempt to get your ult's damage off on as many people as possible do NOT constantly switch targets in an attempt to do so. There's not really much point in damaging and stunning someone just to have them regain safe distance because you're looking to do the same to someone else. Switch targets after your primary one is finished or completely removed from the fight to get the best out of your ultimate.