Kayn is binary: his build must amplify a clear identity. Any hybrid approach severely reduces impact.
Long Sword
Lethality + MS for roam and assassiner in Shadow
anti-shield for burst assassin Shadow Kayn
Slow on W and Q, penetration for burst Shadow
Boots of Dynamism
Boots of Dynamism
Stasis
his wall traversal (E) allows him to engage by surprise to activate First Strike.
Scales AD in late game to maximize its damage in Rhaast form or Shadow assassin.
Finishes isolated targets with the R Shadow Step that the plunges in the shadows.
Attack speed to accumulate the orbs Darkin/Shadow faster and transform.
dashes E through walls trigger penetration on emergence.