Seeing other schools take ~50 damage using Empower while a Death takes ~500 damage is not fair. I don't mind taking the ~500 damage, but why can other schools yield the exact same effect with 90% less damage taken?
Suggestion: Changing Empower TC into a Moon spell, dealing about 300-500 Moon damage with 100% pierce. This way Death stats would not affect the damage taken, all levels can still use the spell effectively, and the backdraw applies to every school equally.
I assume you mean have it do moon damage? Since deaths already learn this from a spell quest, it wouldn't make sense to have them do a new one for a different spell.
I do like the idea of having it deal moon damage, since Dark Pact already has that. Empower, Sacrifice and (maybe) Bad Juju should follow suit.