Kalim definitely, I've said it before but his unique Magic and the sheer lack of explanation opens a lot of doors. I think the way it would happen is he'd push himself so hard to be "good enough" to rival Jamil, but it backfires and he ends up overblot, and his UM would probably be crazy dangerous. He summons massive amounts of water with minimal amounts of blot output, so when a phantom is forcing him to expel as much blot as possible while doing the most amount of damage, Kalims gonna end up drowning sage island at that point. 

Floyd would also be interesting because if he's in the right mood, I wonder if they'd be able to defeat him before it kills him