Freeze control/immunity is becoming too stale in the game. Why not another control skill such as Drowning? I previously suggested this could be a DoT, but it would also be good as a way of controlling enemy monsters (they are struggling to breathe so much they forget to attack?).

Enypiast and Mystery both have possession skills. Enypiast has skill for Immune to Freeze to all and Mystery her special is gives Immunity to possession

Edited to add: Famperium has Possessing skills, bleed, and steals life Has special of heals 50% Removes negative effects and gains triple damage and gains an extra turn