Vultures only give you 2 models. Raspy can use any Frozen Heart model in her crew, and she's got ways to hand that out if you don't have it already.
Honestly, as much as I like Perdita, Seamus (oh, how I love Seamus), the gremlins, and the twins, Sonnia and Rasputina are probably my favorite Masters. They just ooze character, and they can be brutal on the table. They also make for one hell of a battle when they clash. santiago might be my favorite Minion, but the fire and ice women are the top of the Master pile.