Yeah I really didnt expect to be oom in frost, frostbolt costs 12k mana for 1.52seconds to cast at my haste level.
Throw BL in this, and a little bit of bad RNG, and you got it. I don't know why the mana cost is so high, or at least yeah, make evo to restore 100% mana for frost (maybe fire, I don't know if they have this problem, I don't think so)