Duel and wear-down your opponents as a bruiser with sustained damage.
Burst damage and target access
Hitting a champion with 3 separate attacks or abilities in 2s deals bonus adaptive damage.
Gain a burst of Lethality and Magic Penetration after using a dash, leap, blink, teleport, or on leaving stealth.
Collect eyeballs for champion and ward takedowns. Gain permanent AD or AP, Adaptive for each eyeball plus bonus upon collection completion.
Heal for a percentage of damage dealt with your abilities. Increases with each unique takedown.
9% attack speed, 9 ability power or 5 attack damage
Takedowns restore health and grant bonus gold.
Deal 7% more damage to low health champions. Gain AD/AP after kills or assists.
Electrocute on Kayn grants you the burst damage needed to get going early with a kill or two to snowball the game in your favor.
Kayn is one of the biggest abusers of Sudden Impact as simply casting [Q} will grant you Lethality.
Eyeball Collection is all about fighting from the get-go and getting takedowns to scale into the mid-game.
Because Kayn likes to duel and spam his abilities, Ravenous Hunter provides a lot of extra healing in those fights. It also pairs nicely with Rhaast's passive.
Kayn's farly large AoE on [Q] and [W] allow you to hit multiple targets in teamfights, picking up assist/kills and grants you massive healing from Triumph in teamfights/skirmishes.
Coup De Grace pairs well with Kayn natural assassin tendencies, and can greatly improve the damage of your [R] when looking to finish off a target.