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.
Gwen can still damage enemies outside her Hallowed Mists, especially with her Ultimate's range.
Some of Gwen's Abilities can apply her passive to multiple enemies, so aim them at groups to get maximum damage and healing.
Always be Attacking - In addition to dealing bonus damage, Gwen's Attacks empower or reset many of her Abilities.
The Kassadin Gwen synergy stats shown here demonstrate the areas of his gameplay that do better (or worse) when paired with Gwen, 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 very large drop in his KDA (ratio of kills and assists to deaths) when paired with Gwen. His KDA decreased from NaN to NaN. This fall shows that Gwen helps Kassadin perform not as well in competitive League of Legends rounds. Yet, the small difference indicates that this performance change is not very impactful.
When Kassadin tries to synergize with Gwen, he gets a little drop in his total damage output. This difference may demonstrate that Gwen does not provide protection for him to dish out more damage or that her presence on the team also helps extend the match's duration. Similarly, when Kassadin is played together with Gwen on the same team, he usually scores many fewer killing sprees compared to when he plays without Gwen. This is contrasting evidence that he is worse when playing synergisticly with Gwen.
Additionally, when Kassadin plays with Gwen on the same side, he typically takes a little less damage than when he plays alone. Getting dealt not as much damage could mean that Gwen does a decent job of protecting Kassadin in teamfights.
There is no universally accepted best ally for Kassadin that will no matter what be his ideal synergy. However, Gwen is a not very good ally for Kassadin. By playing on the same side as Kassadin, she drops their win rate by -3.0% to 47.0%. This shows that there is a negative strategic relationship between Kassadin and Gwen that results in them performing worse together than alone.
Gwen has a much lower diffuclty than Kassadin. That means you don't need to be cautious when finding Gwen comrades to play with, as they will need a much lower level of skill to be able to do well with you.
Fighting cooperatively, you should expect to witness an overall large increase in your team’s capability to deal magical damage. Combined, these champions can deal quite a lot of AP type damage.
Conversely, by grouping Kassadin and Gwen together, you will not be providing your side very much crowd control. Plan to pick other champs on your team that helps cover this hole in their kit.
Regardless of the skill of your Gwen ally, you should focus on increasing your income, warding to avoid ambushes, and taking down objectives. If you heed this simple advice, you should do well anyway.
To truly master Kassadin in order to work well with Gwen during both the early game and mid / late game phases of League of Legends games, you should keep reading to learn a few extra tricks and insights into this champion pairing. If you pay attention to the build and suggestions presented here, you will increase your win rate significantly.
The best items to prioritize in your Kassadin and Gwen synergy build consist of Seraph's Embrace, Malignance, and Rod of Ages. When Kassadin included at least these three finished items in his build, he did significantly better when fighting alongside Gwen than with most other commonly used builds. In fact, Kassadin had an average winrate of 47.0% helping carry Gwen with this build.
To have the highest probability of crushing your oponents, you should take 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 chose for Kassadin and Gwen pairings, this composite of runes yielded the greatest win rate. Notably, these runes provided a 47.0% win rate overall.
By default, tips, stats, and builds on how to team up Gwen with Kassadin are given for all skill levels combined. If you want to narrow the stats and builds to an individual rank, you can use the selection menu located earlier on the page.