I just tried to use Blizzard 2 to get DPS and its.... not recommended. While it seems good in theory, it sucks up mana like nothing else. I think the idea behind Tri-Disastor was to bind enemies, then use Bane to affect all enemies (DoTs dont break bind). However since they usually resist, I never find myself trying this and the bind is almost instantly broken by other DPS the second it goes off. Blizzard 2 can be used as a means of holding off enemies when you get agro, though that never happens in my experience and they usually beat me down before I know what hit me.