Alter Ego (-10 FP): After every full rest, [character name] must make a Control Check (1d12 + Smart Ass) to gain control over their body. The DC is based on the other creature in their body (6 + its Smart Ass).

If the Control Check succeeds, they control their body until their next full rest. If it fails, the other creature gains control of their body as its own until its next full rest. They do not have access to the creature’s Features and it does not have access to theirs, unless the Game Master rules that the Features are sufficiently physical.