When an enemy unit leaves play
From SWU Holocron
Rulings for trigger When an enemy unit leaves play
Q: If a Leader is defeated does it trigger a "When an enemy unit leaves play" effect?
Examples: Boba Fett, Collecting the Bounty, Leader, When an enemy unit leaves play
A: Leaders are always in play despite what state they are in (Leader vs Unit). They enter the game in play as a Leader, and remain in play as they transition to a Unit and potentially back to the Leader state if they are defeated. Abilities that reference when a card enters play or leaves play won’t interact with a Leader being deployed or defeated.
Source: https://garbagerollers.com/2023/11/08/rules-recap/
