In this guide I will show you how I play and defeat Viktor. Whether you wish to follow this guide or not is up to you as I am just showing you the way. This is all base from my own opinion and shouldnt be considered as a fact. Its how I play as him, as well as defeating him.
How to Play and Defeat Viktor
First Thing to Do
Take a look on his abilities and get a chance to understand. Its actually rather not difficult as he is the most basic character to play as, he is also very useful character as well if you know how to use him well. Here are his abilities.
Assault rifle: His weapon, its fully automatic and does damage to enemies. Fire rate is pretty good as well.
Iron Sights: You aim your weapon, useful to increase accuracy. Its also useful to pick enemies off from a distance. While the damage is not as big as close range, it can help deliver damage while enemies are not aware of you. I dont recommend using this if they are up close to your face though, remember to stop aiming because spraying can be useful too if enemies are difficult to kill in close range.
Hustle: You have the ability to sprint. Thats all there is to it. No cooldown and you can use it as much as you like, you dont get tired. It can be useful for flanking too.
Frag Grenade: You throw a grenade, useful against a good amount of enemies or one tough enemy. You can use it in different ways such as throwing it while in cover. You can even use it on walls or ceiling to bounce it off. You can hurt some enemies that hides behind shields that way if you know how to use it well.
Barrage: Viktor's Ultimate, brings out the artillery from above. It doesnt effect on inside buildings, you can still use it inside as well. All its required is for you to get a visual on your enemies. I dont think doing it through walls would effect either even if you see through them. It has to be right there where you can actually see them. Its also useful to use on group of enemies sticking together.
This is the loadout I use for Viktor, each of them benefits on Viktor's gameplay.
Hit and Run: Your speed increases after you get a kill, this is useful for advancing or retreating.
Compensator: It reduces your recoil when aiming, this is reliable if you wish to pick enemies off from a distance without getting shot at. This can be also useful when fighting.
Reflexes: Helps you aim sight faster, good for reaction timing.
Grenadier: Every enemy you hit with a grenade reduces your cooldown by 1 second. Useful on group of enemies so you can have lesser cooldown, allowing you to throw another later.
Scramble: Perfect to use in means to escape, especially if injured because this helps you take less damage. This only activates when using Hustle. This can also help for advancing as well.
My prefer Talent is burst mode. Reason so because not only is it effective on close range, but far range as well because of its increased damage. Its proven to be dangerous if used because of its damage, and you waste less ammo that way before reloading. On close range when fighting flanks, you can always spray, and each hit is rather dangerous for flanks as well. So its possible to even kill flanks with this talent as long as you dont aim so constantly.
Here are the items I use either permanent or optional. Any items I dont mention are the ones I dont use at all. This varies on the enemies I'm facing.
Helps improve your survival, making it harder for enemies to kill you. This will also help when fighting flanks because they do big damage as well. Most of the attacks from flanks are usually direct hits as well.
This can be effective for movement speed and hustle too, useful for flanking.
Personally I dont use it so often due to Viktor's amazing 3 round burst damage but I tend to use it if I must when it comes to facing enemies having medics with dangerous healing abilities such as Furia, or any medics thats proven difficult for me to kill with them healing others. Otherwise, if they dont have a medic or if its not a strong medic then this doesnt matter much to me.
Kill to Heal
Simple explanation, you kill someone and you get healed, you are your own medic. This can stack with Haven since it helps you reduce the damage you take from direct hit. Beware of enemy's Cauterize though.
Dangerous item for Viktor. Helps you recharge your Ultimate quicker. Considering Viktor's Ultimate can be easily reached 100%, using it makes it even more easier. It happens to help on most situations when dealing with challenging enemies, good for making enemies force to spread out more often, and can be used to injure a frontline badly if taking all those hits, which can allow you or your team to finish them off.
Any items I dont mention are either not helping me or not helping me much. Either because I already knew a strategy without it or I already have whats needed to help me win.
Playing as Viktor
As Viktor, you are a soldier. You go in, fight enemies and do what needs to be done. Viktor can potentially behave as a flank due to having the ability Hustle. His 3 round burst can kill enemies with a good amount of damage, conserving ammo as well. When dealing with flanks such as Maeve, who is usually well known to jump and attack constantly, you can just stop aiming and spray at her, this strategy is also useful on other Flanks that moves around you, aiming at them will be more difficult than not aiming when it comes to close range fight. Every hit does big damage, especially close range. However, its much more easier to win against Flanks if you have Haven because without it will be more difficult due to their high damage and their tactics which usually involves making it difficult for you to aim.
Attacking enemies from a distance is wise as well, especially if they dont pay attention to you. Makes them easier to hit, and with increase damage from 3 round burst it can be effective also.
Barrage is useful against Frontlines and can harm enemies if they are together. You can kill a good amount of enemies if they are weakned as well. Viktor's Ultimate recharge pretty quick even without Morale Boost, but with it is rather very effective to use.
Finding cover is also helpful for Viktor, helps you get away if you are in a tough fight. Too risky to fight in the open.
Fighting Against Viktor
Theres really not much actual tips against him. Just attack him when you see him. As said, he is just a soldier. Only thing to be aware of is that he can retreat if he feels he is in danger. A smart Viktor player would pick off weaker enemies before going for the stronger ones. Mostly the ones with low health, only picking a fight with frontline whenever he feels necessary. If he uses his ultimate Barrage, just stay out of his view until it goes away (whether by using 3 barrage attacks or take too long using it). Watch for his grenade as well, it can either kill you or do some damage depending on the range and your health, especially when taking cover.
Viktor is a soldier, with really not much to explain about him as he is the most basic character in the game. If you have experienced different FPS games then you know he is really that simple to use. He is also reliable as well if you know your tactics with him. Despite being "Damage", he can behave as a "Flank" thanks to his Hustle ability. The only cooldown he has is just grenade, everything else is infinite use, excluding his ultimate (since as usual it requires to charge up so I dont count it).
Despite of this, Viktor is no One Man Army. He needs his team to help him if he gets overwhelmed, and he cant take as much damage as well. Flanks can be potentially dangerous to him if he's off guard.
So whether you think this guide is a good idea or not is entirely up to you, respectively.
Before You Play as Him
Visit the shooting range and check his loadout, make sure it helps benefit you in your fight. Especially his Talent "3 round burst". Remember the tips I have given you, VIktor can be potentially dangerous if used right. But again, he's not a One Man Army. You can easily kill him if you are aware of him, if you are not then he can probably kill you while you dont pay attention to him, even if you react too late.
Whether you want to use this idea or not is entirely up to you.