After a few game with a unrefined Dragon Priest where I just added a few new cards just because...well they're fucking new and why not.
Dragonfire Potions. It has been excellent for me, replaced the 2 Holy Nova and in about 10 games...I never missed the healing from Holy Nova, and the extra 3 damage is just awesome, sure it can affect some of my minions but hasn't been a big issue...trade off has always been worth it so far.
Draconid Operative. It replaced the two blackwing corruptors. First it's a dragon so synergize well with the deck obviously, and also isn't gonna be a target for Dragonfire Potion which I thought would be nice. Discover is a nice mechanic, you almost always end up with something useful. It has better stats too.
Wrathion. It replace priest of the feast. I drew between 1-5 cards...once was 1, and once was 5...the other were all 2-3...I think in my deck 2-3 will be the norm so it's a pretty good.
Deck isn't optimized by any means, just wanted to test these 3 cards since they were easy to fit without changing the entire deck.