Just an FYI: I came up with a far more interesting narrative way of doing this - instead of a zombie, the boss is a ghost and the hero uses a spell to bind them to an object (for those who've seen my other threads, this is how Ruxpin, my animated psychotic teddybear, is created.) Though this is a one-time thing since the spell is consumed (or actually doesn't even exist since this was all done using eventing)
However, I'm considering another area later that follows this idea directly. So, I'm still open to suggestions and idea. I really like the idea of revive/life/etc returning the enemies to living enemies and changing their skill set to match, just unsure how I want to implement it (more xp or less, harder battle or easier, etc) so thank you all for your suggestions.
On that note, how would this be done simplest? I suppose one could event all the battles to change the enemies, or would it be possible to write a common event without a hundred different conditional branches for each and every battle? (Or even somehow add it to the enemies DB entries?)