This is stupid good in Anarch. Most of their faction Id's have been treated as plug and play for a while now, save for a tech choice or two (Excluding Noise.) Now you can start a game as Reina, Quetzal, Valencia, or even MaxX and then transition to Whizzard or Edward Kim as the game goes on. As for other factions, I think Criminal is going to be the faction where Rebirth is used most. The Professor might use this to transition to either Kit, Kate, Chaos Theory, or Nasir, but I'm not holding my breath.