Crystal Masters, also known as Greeble Corruptors, are a type of Evilized Greebles that hold the ability to evilize any creature they see with their crystal staffs. Although they aren't fought in the storyline of Skylanders: Swap Force, they can be fought in the Bonus Missions.
Trivia
- In a scrapped voiceline, they're called Evilizer Masters.
- In Battle Arenas, there are much larger versions called Cage Masters which are not directly fought but can perform a variety of magic depending on the arena.