Not sure if Mana Blast is new or if it was in FE and I just never got it, but it's seriously OP. Roughly 20 mana for a single shot for 700-900 damage. Granted it has a 1 round cast time, but that epic fight against 3 dragons at once it was over in 2 rounds because I just had 3 heroes cast it while the dragons ate some sacrificial spearmen. Even when one resisted they took 300+ damage.

Just seems like someone missed a decimal place somewhere. Also I'm not entirely sure what its damage "type" is, or if spell resistance is the only chance a target has.