Kassadin's ultimate has many uses and is on a shorter cooldown than most, use it often.
Kassadin has multiple item paths; he can go caster via Mana and Ability Power or anti-caster with Cooldown Reduction and Magic Resist.
Try to get the Ancient Golem buff to counteract Riftwalk's increasing Mana cost.
Don't go in first to a large teamfight. Wait for your teammates to initiate.
Tumble has many uses, but it cannot pass over walls.
Condemn can be used to both pin targets to walls to ensure a kill, or to escape a pursuer.
The Kassadin Vayne synergy stats shown here demonstrate the areas of his gameplay that do better (or worse) when paired with Vayne, compared to his overall stats. Significant differences are areas of focus that highlight how his gameplay changes when paired with this other champion.
Overall, Kassadin sees a large worsening in his KDA (ratio of kills and assists to deaths) when paired with Vayne. His KDA decreased from NaN to NaN. This worsening shows that Vayne helps Kassadin perform not as well in competitive LoL matches. Yet, the small difference shows that this performance change is not very impactful.
When Kassadin plays on the same team as Vayne, he observes a little decrease in his complete damage dealt. This change could demonstrate that Vayne does not provide cover for him to deal more damage or that her participation also helps extend the game's duration. Similarly, when Kassadin is played alongside Vayne on the same side, he usually scores many fewer killing sprees compared to when he plays without Vayne. This is contrasting evidence that he is worse when playing with Vayne.
Additionally, when Kassadin plays with Vayne on the same team, he usually takes a little less damage than when he plays alone. Taking not as much damage could mean that Vayne does a decent job of covering Kassadin in teamfights.
There is no ideal companion for Kassadin that will 100% of the time be his #1 teammate. Yet, Vayne is a relatively poor companion for Kassadin. By locking into the same team as Kassadin, she lowers their win rate by -2.0% to 48.0%. This clearly indicates that there is a negative synergy between Kassadin and Vayne that allows them to perform worse together than alone.
Vayne has a lower difficulty than Kassadin. That means Kassadin players don't need to be careful when arranging Vayne allies to play with, as they will have to have a relatively low level of skill to fight well with you.
Working together, you should witness an overall large increase in your team’s capability to dish out massive AD. Combined, these two can tear through the other team with a lot of physcial damage.
Conversely, by aligning Kassadin and Vayne together, you probably will not be granting your team much engage. Make sure to bring other champs on your team that helps cover this relative gap in their potential.
Regardless of the ability of your Vayne teammate, you need to focus on increasing your gold income, staying alive by avoiding foolish fights, and clearing objectives. If you follow these simple suggestions, you should do well anyway.
If you would like to learn all of the intricacies of Kassadin in order to work well with Vayne during both the lane and mid / late game phases of League of Legends games, you should continue reading to gather some more tips and tricks for this champion pairing. If you listen to the build and tips presented above, you should grow your win rate by a lot.
The most crucial finished items to prioritize in your Kassadin and Vayne synergy build include Rabadon's Deathcap, Malignance, and Rod of Ages. When Kassadin combined at least these three finished items in his build, he did significantly better when fighting alongside Vayne than with most other typical item sets. In fact, Kassadin had an average win rate of 48.0% when playing alongside Vayne with this build.
To have the highest probability of coming out on top against your oponents, Kassadin players should equip the First Strike, Magical Footwear, Future's Market, Cosmic Insight, Sudden Impact, and Ultimate Hunter runes from the Inspiration and Domination rune sets. Out of all the rune sets players picked for this team composition, this combo of runes resulted in the greatest win rate. In fact, these runes gave a 48.0% winrate overall.
By default, tips, stats, and builds on how to team up Vayne with Kassadin are given for all skill levels combined. If you would like to narrow the stats and builds to a particular division, you can use the selection menu earlier in the counter matchup guide.