Be careful about how close you let Viktor get to you. Viktor's control of the battlefield increases with his proximity to his opponent.
Be aware of how many augments Viktor has upgraded by looking at the color of the light on his staff (purple, yellow, blue, red).
The stats shown on this page clarify several significant Senna vs. Viktor counter statistics that may help us distinguish the differences and similarities between the pair. For instance, Senna’s KDA ratio ([kills + assists] / deaths) of NaN is more than Viktor’s ratio of NaN, demonstrating that Senna may be more central to her team's team fighting effectiveness than Viktor. This observation is in large part caused by the differences in assists.
Senna usually has a slightly smaller longest killing spree than her foe does. On average, she takes a similar amount of damage to Viktor. This is usually reflective of different amounts of tankyness, but it can also imply that the champ with increased health has less mobility and thus is unable to kite away from additional harm when poked or engaged.
Both League champions are great champions. Both have their strengths, weaknesses, and counters. In League's current meta, Senna usually wins when playing against Viktor, with a 51.6% win rate. As a result, Senna makes a good counter to Viktor.
While Senna does have a higher win rate compared to Viktor, when on opposite teams, Senna also has a lower difficulty level that makes her a less complex champion to develop with. You should be careful when picking Senna into Viktoras her relative depth means you may not be able to reach her full potential without a significant amount of practice beforehand.
Moreover, Senna has a good amount of utility and CC, a similar amount to Viktor. This often makes her just as valuable during teamfights, especially when fighting champions with a lot of burst damage.
While there is not a single best champion overall in League of Legends, in Senna vs Viktor matchups, Senna is the better champion with a higher win rate, less champion complexity, and a similar amount of utility to help out your allied champions during late stage team fights.
Senna is a decent counter for Viktor. You will do well by focussing your play on keeping up your CS and taking out objectives. If you do that, you should do very well as Senna against Viktor.
To truly master Senna to counter Viktor during both the early game and mid / late game phases of League of Legends, you should keep reading to learn a few extra tricks and insights into this matchup. If you pay attention to the build and tips presented above, you will grow your win rate by a lot and be closer to League of Legends pro players.
Senna typically gets less CS relative to Viktor. Champs who on average don't acquire much CS often don't need much CS to be effective, such as supports. These kinds of champions are capable of scaling well off of their skills, stats, and first items alone. Yet, champs with a lot of CS, such as hyper-carries, typically have to have a lot of items to be effective. In either case, try to do better than the values displayed on this page to do well.
The best items to have in your Senna versus Viktor build consist of Infinity Edge, Rapid Firecannon, and Bloodsong. When Senna included at least these three pieces in her build, she did a lot better when facing Viktor than with many other commonly used item sets. In fact, Senna boasted an average winrate of 51.6% battling Viktor with this counter build.
To have the best likelihood of vanquishing Viktor as Senna, you should take the Fleet Footwork, Presence of Mind, Legend: Alacrity, Cut Down, Bone Plating, and Revitalize runes from the Precision and Resolve rune sets. Out of all the rune sets players picked for Senna vs Viktor clashes, this set of runes resulted in the best win rate. In fact, these runes averaged a 51.6% winrate overall.
By default, tips, stats, and builds on how to beat Viktor as Senna are presented for every ranked division. To narrow the stats and builds to an individual rank, you may use the selection menu earlier on the page.