This deck basically can beat Heroic Drakkisath without worrying about the RNG of the cards he plays. The only thing you have to do is mulligan for Deathwing.
Once you have Deathwing in your hand, you just stall and remove any minions he plays until he plays Mindgames which should happen around turn 4-5. Mindgames will pull Majordomo Executus from your deck, you play Deathwing, clear his board and turn him into Ragnaros, putting him on 8 HP and removing all his armor. Next turn you swing for 12 and kill him.
Drakkisath's Command is the only thing that can shut you down after playing Deathwing. To prevent this, you need to set up a Spellbender before playing Deathwing or you need to have baited him to use it on a Mirror Image or Mirror Entity. Otherwise you have to hope he doesn't have it in his hand.
Most of the spells can be swapped out with whatever you have available. You just need 28 spells and the 2 minions. The only exception is probably don't run Counterspell because that will just get Mindgames countered and won't actually protect your Deathwing from being killed.