Viktor Build Guide by Vicksay
[11.21] Vicksy's Updated Master Viktor Guide for Season 11
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Runes: Phase Rush / kiting and scaling
+9 Adaptive (5.4 AD or 9 AP)
+9 Adaptive (5.4 AD or 9 AP)
+8 Magic Resist
+9 Adaptive (5.4 AD or 9 AP)
+9 Adaptive (5.4 AD or 9 AP)
+8 Magic Resist
+9 Adaptive (5.4 AD or 9 AP)
+9 Adaptive (5.4 AD or 9 AP)
+8 Magic Resist
+9 Adaptive (5.4 AD or 9 AP)
+9 Adaptive (5.4 AD or 9 AP)
+8 Magic Resist
Hello everyone! Welcome to my new Viktor guide. My name is Vicksy, I'm a Master tier mid laner, and I'm well-known for my in-depth MOBAFire guides, my Zoe, Aurelion Sol and Ahri guides are the top rated guides in their categories. I've been playing since the start of Season 3 on the EUW server, and I've been a full on mid main since Season 4. I have achieved at least Diamond 1 every single season since Season 4, hitting Master in multiple seasons, peaking at 224 LP. My favourite champions to play are mages such as Zoe, Ahri, Viktor, and Vel'Koz among others. I am a partnered Twitch streamer and YouTuber, and I like to stream every single day! Feel free to come check me out and ask me any questions you may have, whether it be on stream or on my other socials below!
I have been playing Viktor since Season 6, and he is another one of my favourite champions, and my favourite all-time try hard ranked pick. I always needed a late game power house champion for when my other champs were countered, and Viktor fit fantastically into my champion pool. He has his ups and downs in League where at times he's really weak or extremely strong, but right now after his mini-rework I feel like he is in a great spot. I like that you can play him in multiple different ways, how he can at times be a lane bully and also a farmer, so unlike most champions it never feels like a 'bad' game to pick him - you can play around a lot of situations with him. I also love his ultimate, the instant point and click interrupt will help you in a wide variety of match-ups where without it you'll feel otherwise helpless. This guide will show you step by step how to maximize your Viktor gameplay and climb the ranks!
+ Scales like a monster
+ Point and click instant interrupt
+ Strong, save waveclear
+ Immense AoE damage
+ Great at kiting
Viktor has always been known as a champion with crazy late game potential - once you are able to get over the early game with this champion, you'll see how devastating his late game damage truly is. Almost all of his abilities are AoE too, which allows you to disrupt the enemy team massively. Once Viktor has his first upgrade (E) you'll be able to farm with ease, and you'll generally be the main reason in games where the enemy team can't take towers without Baron Buff because it's so strong and decent range. Because Viktor isn't played that much, a lot of people don't realize that his ultimate interrupts channels, and this can catch out a lot of people by surprise and is very strong. Once he has all of his upgrades complete he becomes a kiting machine (literally), with a decent movement speed buff on his Q upgrade, and also a slow on all of his abilities too.
- Waveclear locked behind Hex Fragments
- No raw mobility
- Highly reliant on hitting skill-shots
- Scaling pick
Because of Viktor's recent passive rework, while it allows you to build other items than the Hexcore, having his new passive with collecting Hex Fragments actually makes him quite snowbally. You can get a couple of early kills and have your first upgrade extremely early, or the worst case scenario is you having augment only through CSing, which can take quite a while. He has no raw mobility and squishy, which makes him a prime target for a lot of assassins which are roaming the meta right now, and allows him to be very easily focused. Another thing about the meta is games are determined generally in the first 10 minutes - this doesn't allow Viktor to shine where he wants to be as a late game pick, but if you're winning early then you'll be a monster later on.
|This rune is the best selfish choice to keep yourself safe. It's a whole MINUTE cooldown shorter than Heal, it protects you against more damage, and it is better vs. Ignite as it doesn't cut half the shielding power - you definitely want to be running this vs. assassin lanes such as Zed or Talon, or in an overall game where so much burst exists on their team.|
|You're probably thinking: Ignite on Viktor?! Viktor can actually be a decent lane bully, and his damage at level 6 is actually quite scary, taking this gives you that extra oomph to get the early kills to help you snowball, and it's great in match-ups where you can be really aggressive. A lot of champions in the game nowadays have really strong healing so having an on-demand Grevious Wounds also helps a lot, I thoroughly dislike building Morellonomicon on Viktor as he has a wide variety of items that are just a lot better on him, so if I can justify not needing it that badly you'll see me running this.|
|Take this when the enemy team has very devastating CC that you need to stay safe from, especially from junglers like Elise. Rammus and Sejuani, mid laners such as Twisted Fate and Veigar, supports like Morgana or Braum, tanks such as Shen or Maokai, or marksmen such as Varus or Ashe. Keep in mind you do not have to take Cleanse versus only one champion that has CC, but if it's the enemy jungler or mid laner that has it along with it being unavoidable or easy to land, I highly recommend getting used to Cleanse and taking it.|
|A niche pick on Viktor. You don't take this spell to gank bot lane permanently with it, but rather for a more secure laning phase and to match base timings with your opponents basing for high priority items, or if you're just vs. a perma shoving match-up that will most likely not be able to interact with you, or just vs. another Teleport user so that you don't lose that much farm.|
There are multiple different keystones and rune pages when it comes to playing Viktor, and each one has a situation where it's better than the others. You can also use different secondary runes based on the game.
|The perfect keystone to compliment Viktor's kitey, DPS nature. It allows you to continue chasing and also allows you to get away when you need to, which is perfect especially for early laning because you have no innate movement speed. It also gives you slow resist which helps you stick to people for longer!|
|A pretty standard option for mages, you need mana so you take this! It gives you flat mana per stack, but once you have it fully stacked it also gives you 1% of musing mana every 5 seconds. While not great early game, it can help a lot in teamfights where you need that little bit of mana to cast one more ability which can make all the difference.|
|This rune has seen some changes in pre-season, with the changes to cooldown reduction becoming ability haste. It offers 5% ability haste at level 5, and again at level 8 for a total of 10%, but at level 11, on champion takedown, it reduces the remaining cooldown of basic abilities by 20%, which is amazing for a mage like Viktor that likes to constantly DPS in fights, and can even save you by granting you Siphon Power faster so you can use the movement speed to get away!|
|It does nothing for you early, but it slowly ramps up. 10 minutes in it's a small amount of AP, however you start noticing this rune once you hit 20 minutes and higher, and because Viktor naturally wants to get to late game this is a perfect pairing, and I like having the huge chunk of AP for late game insurance. You can go Scorch in some match-ups especially with damage keystones, however I vastly prefer the larger amount of AP to make my late game on Viktor just a bit more devastating.|
|A very standard choice that a lot of mid laners take, more sustain in lane is always great.|
|With Ravenous Hunter being nerfed quite a bit on minions, this is now the best rune to take. Being able to have your main source of DPS in fights up more often allows you to take fights you wouldn't otherwise, and also allows you to have it up more often to cancel those important channeled abilities from the enemy team.|
The bonuses towards your runes are pretty clear cut here, you can opt for 9 adaptive twice for a total of 18 AP and choose between the MR or armour for the final choice, as the HP one isn't very good. If you're in difficult match-ups you can just double dip in the defenses, taking +16 MR or +12 armour, allowing you to get through lane a lot easier.
|This is the primary damage keystone for Viktor. One you have your passive upgraded for Gravity Field (which is always going to be your last upgrade) you gain a slow on all of your abilities, which makes it a lot harder for enemies to dodge it, as it's almost impossible to hit without some sort of CC. Further spell damage reduces the cooldown of this rune, which means you can have a constant barrage of comets especially while Chaos Storm is active!|
|This is Viktor's other great damage option. It's really good for all-in lanes that you can't harass out well early, I personally take this a lot vs. assassins (such as Katarina and Talon because I can't guarantee that I can harass them hard enough pre-6 because of jungle ganks etc, so I want to be able to have burst damage when they all-in me to match them and possibly kill them first. Also great if you need the up-front damage in ranged match-ups as well!|
|This is also a common rune on Viktor. It used to be the common pick before his Gravity Field upgrade got changed to slows, I need to do more testing but I feel like I enjoy Arcane Comet a lot more if I want poke, as I can't use the shielding/healing portion of Summon Aery and its damage gets outscaled by other runes quite fast.|
Glorious Evolution is Viktor's passive. He can upgrade his basic abilities after gaining 100 Hex Fragments. He gains 1 from kills on minions and monsters, and 5 from large minions. He also gains 25 of champion takedowns. Once all three of his basic abilities have been upgraded, Chaos Storm is upgraded automatically.
Viktor's passive has had a lot of changes on the PBE, and this is the final iteration! This makes it so that Viktor is not tied to his Hexcore, but it also makes it a lot longer to get the upgrades. I personally enjoy this, they buffed his Death Ray a bit to help without having the augment early. However, I don't really like that they didn't give him any compensation % AP as he lost a large amount from his Hexcore, which had 180 AP at level 18.
Siphon Power is Viktor's second damage ability. On cast, Viktor shields himself for 2.5 seconds, and hurls a projectile at the target enemy, dealing them magic damage and empowering Viktor with Discharge for 3.5 seconds.
Discharge modifies Viktor's next basic attack to deal bonus magic damage, and it also turns it into a non-projectile, meaning it goes through ability blocking walls like Yasuo's Wind Wall.
Augment Turbocharge: Viktor gains 30% bonus movement speed for 2.5 seconds after using Siphon Power, while also increasing the shield's value by 60%. You should upgrade this ability second.
This is an amazing harass tool and during laning you should always be looking to trade with people using this, as not only does it do a lot of damage, it costs little mana early and grants you a shield. One thing to note is the shield and movement speed is instant from when you cast the ability, so if you're low in a fight ticking down from an ability like Ignite, always look around you for something to target to save yourself or catch up to others!
Gravity Field is Viktor's crowd control ability. Viktor deploys a gravitational imprisonment device at the target location for 4 seconds. The trap arms after 0.75 seconds, and slows all enemise within the field for 0.25 seconds after leaving the area or generating 3 stacks. Enemies still in the trap generate a stack every 0.5 seconds, and once they reach 3 stacks they are knocked down and stunned for 1.5 seconds, but they can't be slowed or stunned again as this only happens once per cast.
Augment Magnetize: Viktor's damaging abilities, excluding Chaos Storm's per second damage, slows enemies hit by 20% for 1 second. You should upgrade this ability last.
You shouldn't directly put this ability under anyone unless they're already crowd controlled - the best way to use this is to cut off chokes and lead their path, as it has a bit of ramp up time before it stuns.
Death Ray - Viktor uses his synthetic arm to fire an energy beam down the target path, dealing magic damage to every enemy it hits. The arm can fire in any direction from any point within range.
Augment Aftershock An explosion follows in Death Ray's wake after 1 second, dealing additional magic damage. You should upgrade this first.
This ability is Viktor's bread and butter tool. It's his main damage output early game while also his waveclear. One important thing to note is that the laser will give a moderate area of vision around where it's fired, so you should always be using this to scout bushes.
I get a lot of questions on how do I aim the laser so well and they have a lot of trouble targeting - Viktor's Death Ray has a very unique way to cast this spell, exactly the same as Rumble ult, and I highly recommend having this on quick cast as it'll help the most. How you aim with this spell is you aim your cursor then hold down E - where your mouse is will be the starting point of the laser. You then use your mouse to redirect it into the direction you want it to go to. I highly recommend going into a custom game to practice this!
Death Ray also has no cast animation - you can use this ability smoothly while walking. Being able to kite in fights while also using this ability correctly is one of the biggest things you need to learn to matser Viktor!
Chaos Storm is Viktor's ultimate. Viktor conjures an arcane singularity at the target location, dealing magic damage to enemies in a radius and disrupting their channeled abilities. The singularity remains active for 6.5 seconds afterwards, dealing magic damage to all enemies within the storm every second and granting sight of the inside area and its surroundings. Chaos Storm can be recast at any time within its duration to redirect it.
Augment Perfect Storm: Chaos Storm moves 25% faster. This automatically upgrades once you've finished upgrading your 3 basic abilities.
This ultimate really ties Viktor's kit together - giving him a lot more AoE damage to to be a big threat, but the most important part is that it interrupts enemy channeling abilities on cast, such as Katarina's Death Lotus and Vel'Koz' life-form disintegration ray
At level 1, you need to decide between Siphon Power or Death Ray. If you can proc Siphon Power easily because you're vs a melee champion, you should take this and harass them hard level 1. If you're vs a standard match-up, you should take Death Ray to proc your Manaflow Band off cool-down and get some poke in from long range.
You take whichever of the 2 damage abilities that you didn't take level 1, so either Death Ray, or more likely Siphon Power.
You then take Gravity Field at level 3, or level up Death Ray another time based on the game. If you're in a full poke match-up where there's no way that you're going to get ganked or be engaged on in lane, then leveling Death Ray is better, however Gravity Field is always the better in general choice if you're not sure which one to go with, as it can help you with ganks and also early on fights with your jungler.
You want to be maxing Death Ray > Siphon Power > Gravity Field, but always putting a point in Chaos Storm whenever you can, at levels at 6, 11 and 16. Pretty standard leveling order for mages, leveling your main damage/waveclear first, then your second damage ability, and then finally your CC.
In this section I'll be breaking down Viktor's item builds. DISCLAIMER: These items are new and I've only had limited testing on PBE, so my opinions may not be entirely correct. From looking at all of them and playing them a little, I've created a list of the items that I think Viktor will use the most. As time goes by and more builds emerge I will refine this section, and I hope you guys enjoy the pre-season fiesta!
|Doran's Ring is back! It's received some healthy buffs, reverting its mana regen passive to a previous state: giving you 6 mana for minion kills instead which I prefer a lot more, as it punishes people that miss CS! It also grants you health if you're max mana, which is pretty awesome.|
|Stealth Ward will be the only trinket you will be taking at level 1, and will be the main choice of trinket for most of your games. Viktor is immobile and squishy, so he needs to be able to have wards to spot to the enemy jungler so he can farm safely.|
|With Viktor no longer having his wave-clear locked to his Hexcore, we'll now need to seek out mana from another item, so we start with building a Lost Chapter. This item builds into the mage Mythics with mana, which you'll always be opting for. With 10% ability haste and 20% of max mana refunded once you level up, the earlier you complete this the better - it'll be very rare for you to be able to base with the full 1300 gold, so you should be buying as many Amplifying Tomes as you can get to work towards it.|
|If you don't have enough gold to buy Amplifying Tomes, you'll be looking at these two instead. You'll go for Boots if you're vs. a very skill-shot intensive match-up, like Xerath or Lux. Getting an early Dark Seal whenever you have 350 gold is always my preference though, it's an amazing item. It is already gold efficient (123%) without any stacks, the +25% healing from potions has been removed and so has the mana, in favour of HP and also more AP from stacks. At max stacks, you can get a whopping total of 65 AP!! That's 1520 gold worth of stacks on a 350 gold item.. THIS IS INSANE!! It becomes 434% gold efficient, more than ANY other item in the game!|
|A Refillable Potion is great, if you have enough gold to buy this early after buying components, get it as soon as possible! Potions that refill every base makes for insane value, so much so that if you have a single Health Potion in your inventory, selling that just to buy this is super worth it. Don't buy this past laning phase however.|
|Control Wards win games - I cannot stress enough how important it is to make sure you get these on the map early, they stay placed indefinitely, and if you're strong enough to protect them you can an insane amount of vision the entire game through it. You shouldn't be only getting these on your early bases - every time have 75 gold on a base pick one of these up and place it around mid, in conjunction with your Stealth Ward you can get a serious amount of vision around mid, which I think Viktor needs to succeed, as he is a champion that is immobile and will naturally get ganked a lot.|
|Sorcerer's Shoes will be your main boot of choice in over 90% of your games. Viktor has huge amounts of damage, and these only amplify it even further. Combined with these boots, Luden's Tempest and it's new passive if you buy it, you can get a huge amount of magic pen which allows you to do true damage to squishies that don't buy any magic resist.|
|Mercury's Treads will be your only other choice of boots. These become necessary when you're vs. high CC and high burst magic damage. If I have to run these, you'll see me running Cleanse as my second summoner spell, with also possibly buying a Banshee's Veil if their burst is really high and unavoidable, like LeBlanc or Evelynn.|
|With Viktor no longer having his Hexcore, we'll now need to seek out mana from another item. Our mana item will build out of Lost Chapter, but we need to decide which one to go. Welcome the new Mythic Items! You can only buy one of them in a game, and you have to choose wisely - you cannot sell either one earlier to then buy the other one later, you are locked into it for the entire game! It also gives special bonuses to legendary items that you purchase (boots don't count). You have to decide whether you want percentage health damage to fight tanks from Liandry's Anguish along with a lot of Ability Haste, or you want burst damage, movement speed and a lot of magic penetration to deal with squishies from Luden's Tempest This is the general rule I'm thinking so far for them, but can change once we test them out properly on live.|
|Rabadon's Deathcap is almost a guaranteed purchase in every game we play Viktor if the game goes long enough, it's perfect for him, it gives him that huge bulk of AP so he can reach his late game damage potential a lot faster. Unfortunately, it did suffer a 5% AP nerf in pre-season and now costs 200 gold more, coming to a total of a whopping 3,8000 gold - so it's not as good as before, but in my opinion still greatly required on Viktor.|
|Void Staff, along with Rabadon's Deathcap, should be built almost every game. It has been nerfed by 5 AP in pre-season, but has been made significantly easier to build into through the addition of Void Stone. Don't be afraid on skipping out on this altogether if the enemy team literally has ZERO magic resist, but that will be a very rare occurrence. They also created another item called Blighting Jewel, which is a mini- Void Staff which gives you 15% magic penetration, pretty awesome while you're waiting to buy the whole thing!|
|Demonic Embrace is one of the brand new items added to the game for pre-season! It only gives HP and AP, but the most important part of this item is that it does max health damage, and also gives you 10 MR and armor if a champion is affected by the burn. I can imagine this being a really insane item on Viktor when vs. such a tanky team, especially combined with Liandry's Anguish to have double percent max health damage, and it also allows you to be tankier if you get all-inned. Each tick of Chaos Storm would refresh this and also your cooldown on Siphon Power is quite low late game, which allows you to refresh it constantly without your ultimate too!|
|Cosmic Drive is another brand new item added for Season 11. It gives AP, health, ability haste (which is the new CDR) and its passive gives you movement speed based on 20% of your current ability haste for 4 seconds. This sounds crazy good on a champion like Viktor where his whole kit is revolved around kiting with movement speed to keep him alive as possible to output the most damage for his team. I tried this on Viktor on the PBE for a large ability haste build (the video is on my YouTube!) and it worked out really well, the movement speed I was getting was insane, and you can also combine this with Luden's Tempest to be super speedy!|
|Mejai's Soulstealer is a nice pick up for Season 11, even though it's still a snowball item. With the buffs to Dark Seal, you'll be buying that a lot more often, so upgrading it will naturally be a lot more common. The cost has been increased by 200 gold and has had a slight stat change - replacing mana with health, which is overall a lot better, the counter to Mejai's is being killed, but the extra HP will help you to stay alive. This item, while only costing 1,6000 gold is considered a Legendary item, which means when you buy this when you're massively ahead, you'll also be gaining the passive for a standard Legendary item that you get from whichever Mythic item you choose. Combine this with Zhonya's Hourglass and you can preserve your stacks really easily!|
|Lich Bane will be your highest priority situational item. In pre-season, it lost its mana and CDR and the cooldown of the proc is higher, which are nerfs across the board but I still think it'll be a good pick on Viktor, however I need to do some more testing. Personally, I love Lich Bane so much and try to buy it every single game, though there are some games where you have to skip it. I use this item on a lot of champions I play, and I love how it just makes your burst damage, push potential and objective taking a lot stronger, and it's especially really strong on Viktor because he has auto attacks anyway because of Siphon Power. I don't enjoy building this item until I have a Rabadon's Deathcap at least, as its damage is increased greatly by AP.|
|Morellonomicon is a really overrated item, and still is in Season 11. With the nerfs it's received over the past year, it's not worth to build it AT ALL unless there are enemies that have a huge amount of healing for it's Grevious Wounds passive, we're talking Sylas or Dr. Mundo terrority. 70 AP for a core dedicated damage item is pathetic. At least now, you can build Oblivion Orb just for the Grevious Wounds, so you shouldn't be completing this item unless you have nothing else to upgrade. BUY THIS ITEM ONLY WHEN YOU NEED IT!|
|Zhonya's Hourglass is a great defensive item. You don't necessarily have to build this vs. only AD threats, it is a great counter to many AP mid laners because dodging damage is a lot better than just soaking slightly less damage. It completely negates abilities such as Syndra's Unleashed Power, Veigar's Primordial Burst and even Karthus' Requiem. I don't recommend getting this early on instead of your core items unless it's absolutely necessary (vs. Zed, Vi and others) as it doesn't offer much damage as other buys. Most of the time you'll be sitting on Seeker's Armguard early on if you need the armor and will sit on it until you finish a Mythic item. Buying it late game however is a great idea, as you already dish out tons of damage with a 4+ item build, and you just need something to keep you alive - a Zhonya's Hourglass can never go wrong.|
|Banshee's Veil is a great defensive item, and it's gotten changed in pre-season slightly. It loses 5 AP, but is cheaper and can now be build out of Verdant Barrier, and is the first time I've seen an item be combined for AP and MR, so this'll help you out in really tough lanes early and you can also sit on it for a while while building other items! I especially love combining this with Nullifying Orb or Mercury's Treads. Pick this up if you're afraid of an AP mid bursting you down constantly (like Sylas or LeBlanc), not only does this item have magic resistance but it has a spell-shield that blocks a single ability, helping to disrupt champions that need to hit all of their spells too correctly kill someone. It's also REALLY good vs. champions that really rely on hitting their crowd control straight up even if they aren't in your lane, such as Sejuani, Elise and Blitzcrank.|
Early game on Viktor you can play aggressively or defensively depending on the lane match-up. You can start with Siphon Power in melee match-ups so you can walk up for an easy Q + auto off cooldown for some quite strong harass early for not much mana, and it also grants you a shield which makes trading with you exceptionally hard, and can be taken in some ranged match-ups too. Otherwise you should start with Death Ray. As Viktor most of the time you'll be taking Manaflow Band in your runes, so you use your Death Ray to poke and also proc this at the same time, however you have to be careful, as Death Ray's cooldown is slightly shorter than Manaflow Band, which means sometimes you can rush using it and not get a stack, so pay attention to just above your hud to keep track of its cooldown.
Now that Hex Core doesn't exist anymore, this allows his early buys to be a lot cleaner. You'll always have priority on Amplifying Tomes as they build into most of the items you want early, like Lost Chapter or Seeker's Armguard. If you can't afford any Amplifying Tomes or you already have your priority items that build from them, you can pick up a Dark Seal and Boots, and sometimes I pick up a Dark Seal early on over a tome - it got buffed massively via AP, they buffed the amount of AP from per stack to 5, which means that att max stacks, you can get a whopping total of 65 AP!! That's 1520 gold worth of stacks on a 350 gold item.. THIS IS INSANE!! It becomes 434% gold efficient, more than ANY other item in the game! I always try to buy one of these early if I can.
When it comes to roaming, being immobile and squishy Viktor isn't the best at it - you're happiest when you can sit mid lane and waveclear while waiting for items. If you're behind or you're vs. someone that can easily one shot you, it can be quite difficult to follow them during roams because they can cut off vision from the bush where they are roaming from, making you walk in blind. In this situation you have to get as much vision as you can through deeper pinks that still spot gank paths and making sure you get as many Stealth Wards out as possible.
For the mid game, Viktor generally starts setting up his tent mid lane to start waveclearing over and over. Death Ray is such a good waveclearing tool, it delays games a lot and allows you to get to late game more to get more items, where you truly shine. If you're having a rough time, you should not worry as Viktor scales really hard. A lot of people generally get really annoyed playing vs. mid laners that can waveclear easily, so always be careful as people will try to jump you as much as they can. Generally, if Viktor survives an engage, he can counter engage really nicely and chase after opponents with Siphon Power's upgraded movement speed.
While you still love wave-clearing midlane, you should be aiming to pick up sidelane farm whenever mid doesn't need defending, however you don't want to commit to a split push, as Viktor is very squishy and immobile. While he can win a lot of 1v1's vs. general top lane split pushers, he can be collapsed on so easily which doesn't make it worth it.
Generally around this time, you should have 2-3 fully completed items and maxed Siphon Power and Death Ray alongside level 2 Chaos Storm, you'll start to notice how your damage has ramped up a lot. Fights will happen a lot more as everyone will start grouping, and this is where everyone starts forcing objectives a lot harder. Viktor is great in teamfights with lots of AoE in his kit, and he is also really good at outputting damage on neutral objectives.
Here is where Viktor shines! You want to be constantly grouping with your team in this stage of the game, with your huge AoE damage along with being squishy and immobile, you'll be a huge threat to the enemy team, so you need protection around you. You should never be split from your team apart from picking up extra farm from side lanes that are safe for you to take, you DEFINITELY don't want to be split pushing - a lot of champions that would be still split pushing at this stage are probably late game hyper carries such as Jax or Fiora, and you definitely don't want to get into a fight with those alone. You have a mass amount of AoE damage in your kit, use it in team fights!
Playing Viktor in team fights is very akin to most control mages - stay with your backline and work through the enemy team from front to back. Viktor deals with tanks very easily with his movement speed and insane amount of damage along with his crowd control through constant slows and Gravity Field, and if you're able to get to a squishy you'll one-shot them cleanly especially if you have Lich Bane, one thing to keep in mind is your Lich Bane cooldown by looking at your items. You become a MASSIVE threat your auto attacks with Siphon Power at this stage will easily half health a squishy champion with it, so you have to keep track of it, especially if you find an opening to Flash on their AD carry. Your goal is to do as much damage as possible without dying, make sure you constantly spam Siphon Power to keep up your movement speed buff as much as possible so you're harder to catch.
Another important thing for Viktor is good usage of your Chaos Storm. It's a long cooldown and generally can only be used once a fight, twice in potentially really long fights. You need to decide if you need to safe it to interrupt an important ability like Katarina's Death Lotus or if you need to use it for DPS. One thing a lot of Viktor players do that I notice is that they save their ultimate far too long in a fight because they want to use it on a high priority target - you shouldn't be afraid to use it on the enemy front-line to burst them as fast as possible so your team can clean up the rest of their team easier.
When it comes to objectives, you will shred them and you should focus on doing damage to them whenever you're safe. With your Siphon Power you won't take damage from Baron or Dragon while DPSing! Keep an eye on what your team wants to do, and don't be afraid to ping an objective when you're strong enough.
And that wraps up my Viktor guide! Match-ups will be slowly added in the future. I hope you found this guide helpful, and if you did please give it an upvote to make it more visible, and please post any questions you may have and I'll get back to them ASAP!
Special thanks to Jovy for the gorgeous banners, and for helping me with spots of coding. :3
If you'd like to see my Viktor gameplay live, you can follow my Twitch channel - I play him very frequently, and if I'm not just ask in chat! I stream every single day from 6-7 PM until midnight to 1 AM GMT. You can also check out my YouTube channel for commentated videos, and tips!