The Schism is sort of like Disquiet, a roiling paranoia among people in the area. It's has a negative impact on the Primordial Dream but mechanically it just offers a potentially substantial, 1 to 10, penalty to social rolls in the area. Supposedly the Insatiate can guide the Schism but they suffer the penalty as well.
They'll probably make good antagonists in other games. They'd definitely be on the werewolf hit list, considering Schism wrecks the Gauntlet pretty good.