I think cyromancer is too weak especially when fighting boss. Ice bolt damage is so lame while ice pike CD is long and freezing don’t work on boss. I have got really hard time doing quests that require to kill bosses, waste time run around and wait for skill CD. In contrary, pyromancer just have to put the flame ground which the duration at lv5 is nearly equal to the CD and fireball which I find it’s easy in both grinding and boss quests. Cyro C2 is much worse with only gust and subzero shield added that at high level I only see pyro C2, linker and psychokino is rare and nobody want for higher cyro 
So how about put slow effect for cyro skills that can work on boss, reduce CD or increase the number of hits before overheat.