Avatar: TFT Set 18 trait
Avatar is a single-unit trait in TFT Set 18: it belongs to Lux and is active as soon as Lux is on the board.
What Avatar does
Having an Avatar on your bench or board transforms all other Avatars in your shop to the Trait of that Avatar. An Avatar's chosen Trait is counted twice for Trait bonuses.
From Riot's game data, with the latest patch notes applied; the exact numbers can change between patches.
Lux