Hiya everybody. This guide will discuss my playstyle choices for one of the most under-appreciated champions in the league, Kennen. He's finally coming into favor as a strong AP carry and a force in mid, but has gotten far less love than he deserved before his buff.

There's two slightly different builds listed above, one building a little tanky, enough to properly utilize his ultimate in teamfights, and the other beefier to maximize his stun utility without giving up too much damage. I'll refer to the first as the AP build, and the second as tank.

If you're the tl;dr type, this guide probably isn't for you, as I go somewhat in depth in a few sections. Just look at the item build and move along.

Pros:
Stuns. Everywhere.
Low cooldown nuke
Energy-based
High Mobility
Ninja

Cons:
Naturally squishy
Very common focus target
Prone to CC
Very specific playstyle

I like to rune out my Kennen to be healthier than your run-of-mill build. Kennen's real strength comes from his utility. If you're after pure damage output, there's burst mages much more suited to the role. To this end, I like to rune for a good bit of health to maximize his lane-sustain in the early game and allow aggressive laning when the situation calls.

Greater Quintessence of Health x3
I like to take flat health quints for almost every champion I play. The early game advantage outstrips the value of other quints in most situations.

Greater Mark of Magic Penetration x9
Pretty standard for all AP champs. To this one, Kennen is no exception. Spell pen serves him well at all stages of the game.

Greater Seal of Vitality x9
Kennen is an incredibly strong choice in mid, and stacking him with some extra health can do wonders for you in the laning phase. The late-game bonus doesn't hurt either, when initiating for your team can often fall to you.

Greater Glyph of Scaling Ability Power x9
Once again, standard for AP champs. I feel like this one doesn't require much explanation.

I build my Kennen 9/21/0, and it's hard for me to recommend anything else on him. As an energy champ, the utility tree doesn't really suit him very well, and it's silly to waste points past Archaic Knowledge in offense.

Moreover, a defensive mastery build in conjunction with the above rune recommendations puts you a step ahead of the likely competition in mid, since most mid candidates will put some rune/mastery focus into maintaining their mana reserves in the early game.

While I don't recommend other summoner spells besides Ignite/Flash, (discussed below) if you're not a fan of Ignite, you may want to pull a point out of Harden Skin to buff a summoner spell.

Playing Kennen, I swear by Ignite and Flash in every single game I play.

Firstly, it's important to point out that replacing Flash on Kennen is like equipping an army with pointy sticks. The effectiveness of his ultimate depends entirely on your ability to trap within it exactly the champions you want. To this end, Flash is invaluable. Not taking it severely cripples his teamfight utility in the late game.

As for Ignite, I take it primarily as a personal choice. I really enjoy being able to shutdown champions that rely on health regen heavily, especially since any Swain you encounter will likely be sharing mid with you for the laning phase. I also find that Ignite wins me an otherwise unobtainable First Blood in many situations. It's an all-around great pick, especially considering Kennen's mobility.

Teleport and Exhaust can also be really useful in Kennen's hands, as his utility with stuns can make teleport ganks guaranteed kills, and his ability to penetrate the enemy team and chase with Lightning Rush can save lives and secure kills using Exhaust.

When it comes to harassing in mid, few champions rival Kennen's Thundering Shuriken due to a lack of mana limitations and decent AP scaling. It's important to maximize this advantage in the early game by getting it up to level 5 as soon as possible.

The skill sequence I list here keeps this in mind, but picking up a point in Lightning Rush before continuing in Thundering Shuriken is important to help Kennen's harass, allow easy escapes from sticky situations, and allow for instant stuns even without Electrical Surge's passive stacked up.

I leave Lightning Rush for last after the first point because the spell has little use early game beyond applying a Mark of the Storm and increasing move speed.

I like to start my Kennen with Amplifying Tome and Health Potion. A lot of other Kennens seem to favor Doran's Shield, but I find that having at least one Health Potion handy when playing mid makes for better lane sustain than Doran's items do because their benefits are spread over a much longer time than Health Potion, and can't really prevent going b once a good chunk of health has already been lost. The Amplifying Tome makes for a much stronger early game harass, and can be built into Haunting Guise later.

On that note, Haunting Guise takes a lot of heat as an item for Kennen, or for any champ. I find that while it's obviously very weak as a late-game item, it is just the boost that Kennen needs in lane to ensure domination in mid. More survivability and damage at such a cheap price is hard for me to pass up.

Almost all Kennens I see these days like to rush their Will of the Ancients, picking up the Hextech Revolver as early as possible. While I think the early Hextech Revolver can be a good call on Kennen if you're going to play very aggressively, the Will of the Ancients rush seems silly to me, as the aura benefits don't get their full use in mid 1v1, and building for more survivability early seems to win the lane more often.

I get Rylai's Crystal Scepter next. Once again, for the survivability it adds around the critical period of laning and mid game. It allows Kennen to control space effectively with his ultimate, or the threat thereof, and gives him the ability to initiate early teamfights without too much risk.

Next I go for Rabadon's Deathcap. At this point, Kennen's ultimate has usually just passed it's peak of effectiveness as a damage ability and beginning to stack AP is necessary to maintain it as a game changing ability.

This is where the two builds I propose differ. In the AP build, I like to head for the Will of the Ancients now for the aura as well as the spell vamp on my ultimate. As teamfights become more common, surviving the use of your ultimate as a 5-man stun is of paramount importance to being a force in the late game.

In the tank build, I split for Force of Nature now. I choose MR instead of Armor for my first defensive item because the mobility from Lightning Rush allows you to minimize damage taken from AD carries when using your ultimate, and AP burst is what's most likely to ruin the effectiveness of your ult in teamfights. The decision to take Force of Nature may seem a little strange. I like the movespeed buff, and the health regeneration ends up providing you with a deceptively large buff to survivability.

At level 18, .35%hp/sec * 2778hp + 8hp/sec = 17.723 hp/sec. Even assuming 2.0 AS and 200 DMG on an AD carry, this equates to about a 4.5% decrease in the rate your health is dropping. Pretty significant for some often ignored hp regen.

If you don't like Force of Nature, you can grab Abyssal Mask or a Quicksilver Sash to make up most of the MR, and provide a little extra bonus to damage or CC avoidance.

In both builds, Zhonya's Hourglass is a great pick next. In either case, picking up a good chunk of Armor and AP has its obvious benefits, but the active on Zhonya's Hourglass makes it almost impossible to completely waste your ultimate. At the very least, you'll force the enemy to run out of it, ruining any positioning advantage the other team had in the fight.

Finally, scrap the Haunting Guise and replace it with Will of the Ancients if you don't have it already, or Void Staff, Abyssal Mask, or some situational item of your choice. I show Void Staff in the build because your opponents will scramble for some MR if you're using your ult correctly with the AP build. Otherwise it can decimate an enemy team and almost single-handedly win a teamfight.

Increasingly since his recent buff, Kennen's been getting recognized as the dominating champion in mid lane that he has always been. His ability to stun through so many different spell combinations, and in so little time, grant him a larger area of control in lane that many fail to recognize and respect. Coupled with the lack of unit collisions while using Lightning Rush, he has the potential to bully opponents around in mid lane and consistently win the lane when played correctly.

At the outset of the game, grab an Amplifying Tome and Health Potion as discussed above. If the opponent you're laning against takes a level or two to come into their lane potential (i.e. Leblanc, Veigar, Brand), you can take the first couple minion waves as an opportunity to capitalize on your energy-reliance and establish a health advantage over the opponent by focusing on your harass with Thundering Shuriken. The bonus AP you grabbed should allow you to at least waste off an opponent's potion before they're able to do much to retaliate.

Regardless of who you're midding against, Kennen lacks his stun utility until at least level 2, when you get Electrical Surge, and needs Lightning Rush as well to maximize this potential. Because of this, I usually take until level 3 to try to evaluate my opponent and decide whether I'm going to play aggressively once my stun combo is ready. In a lot of cases, you'll want to just focus on last hitting passively and punishing your opponent for any aggression with a Thundering Shuriken -> Electrical Surge combo. This combo can be pulled off almost instantly on an approaching enemy, and does a staggering amount of damage in the early game.

If you decide to play aggressively, the Thundering Shuriken -> Electrical Surge combo can be supplemented by Lightning Rush to allow your skillshot a hit in most any situation. If your opponent has half a brain, he's going to be standing behind minions whenever possible to avoid Thundering Shuriken. You can use Lightning Rush to pass through the minion wave, score a hit with Thundering Shuriken, use Electrical Surge, and pass back to safety on your side of the minions before the speed and pathing buff wears off. This combo can inflict huge amounts of damage on your opponent in a short time when done right. Just make sure that you're paying attention to the opposing jungler when using Lightning Rush offensively so you don't get caught off guard with it on cooldown. It can be a gank-saver.

In any case, try not to play too aggressively before level 6. This is when Kennen maximizes his lane domination, as the combination of Slicing Maelstrom, Ignite, and Flash can stun lock and kill an enemy under about half health with no problem and without warning.

After level 6, if your opponent is missing a good chunk of their health and overcommits, pop Lightning Rush and flash into them. If you touch them with Lightning Rush, a quick combo of Thundering Shuriken and Electrical Surge will earn you a stun. Alternatively, if you make sure your passive from Electrical Surge is stacked up, you can save Thundering Shuriken for after the stun to guarantee the skillshot a hit. After this stun is when you want to pop Slicing Maelstrom and use Ignite. In most cases, this should net you another stun and ensure the kill before the enemy can do much of anything. I cannot begin to count the number of times I've seen this combo win First Blood, as it only takes a tiny mistake from your opponent and they usually aren't expecting it quickly after hitting level 6.

Kennen's early game dominance is almost unparalleled when played properly, and it's important to note that a lot of his success relies on having a feel for when to play aggressively in lane. If you're new to Kennen, play a little more carefully to get a feel for him before you try lane aggression. If you don't have an understanding of when his stuns and ultimate will win you easy kills, you'll often get caught in sticky situations trying to force it. This is where most Kennens I see fall short. Don't let this happen to you. Maintain your passivity and just harass until the time is right and you'll succeed as Kennen in the early game.

Kennen's teamfight utility late game is what I think sets him apart from other strong AP mids. He can be the deciding force in fights if played correctly with the 5-man stun potential on Slicing Maelstrom. This is why I started playing him in the first place, and why I fell in love with him shortly after.

There are two roles Kennen tends to fall into in the late game. The first is a standard AP burst carry, with his ult being used more for the AoE damage output than the stun utility. This AP build I outlined earlier is for obvious reasons more conducive to this role. The second is as an off-tank initiator. This one is where I think Kennen really excels, and can be pulled off with either build depending on the coordination and composition of the opposing team. Kennen's effectiveness in either role hinges almost entirely on your ability to use Slicing Maelstrom at the right time to ensure your team a victory.

If you plan on filling the first role, you'll want to treat Kennen much like any other mage. Hide in the back of your team at the very beginning of teamfights throwing Thundering Shurikens and swoop in shortly after you've established yourself as an impractical target to focus first.

If the fight at this point is going in your team's favor, you can save Slicing Maelstrom for stopping the enemy escape and securing the ace. Just pop Lightning Rush right when the enemy begins to retreat and use Slicing Maelstrom and Electrical Surge to stun as many of them as possible. The stun in combination with the damage output of Slicing Maelstrom should ensure picking up at least a few more kills that would've otherwise gotten away.

If the fight is NOT obviously trending in your team's favor, you're going to want to Lightning Rush in and pop your Slicing Maelstrom immediately. This, coupled with Electrical Surge, will ensure the majority, if not all of their team gets stunned, and will provide a huge boon to your team, pushing the fight definitively in your favor.

If you choose to go the path of the initiator, and I DO recommend going this way, you'll have to decide on your build sensibly based on the other team. The tankier build will serve you well in any case, but sometimes you can get away with using the AP build without too much risk if the opposing team is failing to focus you properly, or doesn't have the burst damage to shut you down before you get the duration of Slicing Maelstrom off within their ranks.

When you're playing as an initiator, Flash is your best friend on the whole map. Save it for intitiation whenever possible. Before teamfights begin, just poke them enemy team with Thundering Shuriken and Electrical Surge until you catch an enemy out of position, or the opposing team begins to try to initiate. In both cases, if you think it has given you a temporary advantage, pop Lightning Rush, flash in, and pop Slicing Maelstrom.

The reason I say to use Lightning Rush first is its little known, under-appreciated secondary effect. At level 5 it grants +50 Armor/MR for 4 seconds. This is the reason you can get away with playing the initiator even with the AP build, and is a large factor in survivability when using Slicing Maelstrom to initiate.

Once you're in the heart of the enemy team, your choice of when to use Electrical Surge can control when exactly the stuns go out to the enemy team. Try to time it such that each opposing champion gets their 3rd Mark of the Storm right when your team closes on them. You'll get the most out of Slicing Maelstrom that way. Make sure that if you have Zhonya's Hourglass, you use it after you pop Slicing Maelstrom to minimize damage taken as much as possible.

After initiating and getting your stuns out, you'll probably want to get out of the enemy team before you get focused down. If you do, don't sweat it, you've already made quite a mark on the enemy with Slicing Maelstrom and focusing you down at this point is a bad decision, as you've already put out the majority of the AoE damage you can. Your team should be able to clean up the fight quite easily even without you after this.

If the opposing team is a little smarter, and realizes that you're not as big a threat after Slicing Maelstrom, you'll be able to survive easily and continue to throw out what damage you can with Thundering Shuriken. What single-target stuns you can get out at this point should be targeted at carries to minimize their effect on the fight.

Once the fight is in full swing and your ultimate has been expended in either case, Kennen can be used effectively to pile stuns and damage onto carries after passing through their front line with Lightning Rush. If done well, this will effectively remove one of their carries from the fight.

If you can execute Slicing Maelstrom and zone out carries properly in the late game, Kennen is a game changer and can turn almost every teamfight into a victory with ease.

I hope this guide has clarified some of the better practices in playing Kennen, and sufficiently justified the item choices I outlined.

If you have any questions or criticisms please post them and I'll try to reply when possible.