C3PO's Wait for Me!: When there are no other allied combatants, C-3PO escapes from battle.
Hermit Yoda's In Exile: If there are no other allied combatants at the start of a turn, Yoda escapes from the battle.
Wat Tambor's Overseer: If there are no other allied combatants at the start of a turn, Wat escapes from battle.
ARC Trooper Blaster Turret: When there are n oother allied combatants, this object escapes from battle.
The descriptions for Vulture Droid and Malevolence
do not have this wording anywhere. Thus, it's reasonable to assume that they should persist until defeated, like Nightsister Zombie.