Strategy for Hydraulic (cold style):
Stick two “Mind freeze” and two “Flash Freeze” on your bar and try to ensure he’s always on one of them. Regulate him when you can, keep your lowest HP member Ice Wall’d and Veradux on defensive or phalanx. He can’t use “Tick Tock”, and each time you get him to 0 Focus he’ll use that ability that causes him to take heavy damage for three turns. That about covers it.