Quick answers
Who counters Kai'Sa in Wild Rift?
In the matchup data documented in Rift Lab, these are the harder matchups for Kai'Sa: Caitlyn (Dragon / ADC), Draven (Dragon / ADC), Ashe (Dragon / ADC), Varus (Dragon / ADC), Leona (Support), Nautilus (Support), Braum (Support), Alistar (Support). This is a documented matchup list, not a win rate: TheNexus does not publish win-rate or pick-rate figures it cannot source.
How do you play against Kai'Sa in Wild Rift?
Riot's ability text for Kai'Sa describes a dash, leap or blink in KILLER INSTINCT (ultimate); a shield in KILLER INSTINCT (ultimate). Plan around those abilities before a trade or a fight. These notes are keyword matches over the ability text only, not a rating of how strong Kai'Sa is, so read the full descriptions on this page.
What is the best build for Kai'Sa in Wild Rift?
The Nexus-reviewed core build for Kai'Sa, in purchase order: Magnetic Blaster then Guinsoo's Rageblade then Terminus then Berserker's Greaves. Runes: Lethal Tempo, Brutal, Cut Down, Legend: Bloodline, Bone Plating, Coup de Grace. This is a reviewed snapshot (patch 7.2b), not a build ranked by win rate.
Which lane and role does Kai'Sa play in Wild Rift?
Kai'Sa is a Marksman and Assassin by Riot's classification and is played in Dragon / ADC. Riot rates the difficulty Medium. On our tier-list snapshot (patch 7.2b) it shows A tier from its external source, which is a snapshot letter and not a TheNexus win rate.
Every answer here is built from Rift Lab data and Riot's own ability text. Where the data is missing we say so instead of guessing.