What the Rift Lab holds on this champion: the kit as Riot publishes it, the build the lab reviewed, and the matchups it has documented. Anything the dataset does not record is left out rather than filled in.
Riot's own text for each slot, in the order the champion learns them.
Kayn wields an ancient weapon and fights Rhaast, the darkin within it, for control. Either the Darkin will triumph, or Kayn will master Rhaast and become the Shadow Assassin. Darkin: Heal for a percentage of spell damage dealt to champions. Shadow Assassin: For the first few seconds in combat with enemy champions, deal bonus damage.
Kayn dashes, then slashes. Both deal damage.
Kayn damages and slows targets in a line.
Kayn can walk through terrain.
Kayn hides in an enemy's body, dealing massive damage when he bursts out.
The reviewed purchase order and rune page for this champion. Every entry that has a page of its own is linked to it; an item the catalogue holds no page for is printed as a name rather than pointed at a page that does not exist.
One slot, changed when the enemy team changes the problem. These are answers, not automatic purchases.
Ability text and the in-game title follow Riot's official Wild Rift champion pages. The tier letter is the external snapshot shown on the tier list, and the build is the Nexus reviewed snapshot — neither is a win rate.
In the matchup data documented in Rift Lab, these are the harder matchups for Kayn: Rammus (Jungle), Lee Sin (Jungle), Kindred (Jungle), Kha'Zix (Jungle), Vi (Jungle). This is a documented matchup list, not a win rate: TheNexus does not publish win-rate or pick-rate figures it cannot source.
Riot's ability text for Kayn describes a dash, leap or blink in REAPING SLASH (ability 1). 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 Kayn is, so read the full descriptions on this page.
The Nexus-reviewed core build for Kayn, in purchase order: Youmuu's Ghostblade then Serpent's Fang then Serylda's Grudge then Boots of Dynamism. Runes: First Strike, Sudden Impact, Hubris, Eyeball Collector, Celerity. Situational swaps: against enemy crowd control: Edge of Night. This is a reviewed snapshot (patch 7.2b), not a build ranked by win rate.
Kayn is a Fighter by Riot's classification and is played in Jungle. Riot rates the difficulty High. On our tier-list snapshot (patch 7.2b) it shows S 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.
