1. Instant defeat
It's All Inevitable Mechanics - Baylan Skoll - Star Wars Galaxy of Heroes - SWGOH.GG
"Defeated enemies can't be revived and Mercenary allies can't be instantly defeated."
Palpatine's lvl9 reads:
"The first time Emperor Palpatine is defeated, if there is an active ally, the enemy who defeated him takes a bonus turn and then is instantly defeated."
2. Damage immunity
Power. Such as You've Never Dreamed Mechanics - Baylan Skoll - Star Wars Galaxy of Heroes - SWGOH.GG
"Deal Physical damage to all enemies, dispel all buffs on them"
Sith datacron:
"Sith allies start the battle with Damage Immunity for 2 turns (can't be copied)."
But it can be dispelled.
You have a baylon in your skull, smokey boy.