Hearthpwn

I have no idea if this works or not BUT, the deck strat is to:

Reduce cost of Humongous Owl and Majordomo Executus with The Dark Portal. (if dark portal doesn't work mithril rod and thaurissan for backup)

Play Majordomo, give him to your opponent with Treachery, play Humongous Owl and use Plague of flames to kill him which in theory should turn him into ragnaros and then take 8 damage from the Owl.

If both minions are cost reduced by the dark portal only the combo should be 10 mana. And if needed you can reduce the cost of treachery + plague of flames with mithril rod to play Rafaams scheme incase the opponent has more than 1 minion.

Edit: I added sphere of sapience and emperor thaurissan, both for obvious reasons. Removed felfire in the hole (was just a filler card before) and one plot twist as it removes the reduced cost. Still kept one incase you draw both the owl and majordomo before you draw the dark portal so you can reset your hand sort of.

Yes I know this combo probably isn't viable but I just wanna know if it's even possible (no i can't try it yet i am poor with no cards)