Cheap Ragnaros/Executus Priest Deck (Heroic Mode)

Strategy

On Heroic Mode, the Ragnaros form of this boss is simply too overwhelming to defeat fairly. So this deck's strategy is to kill both the Majordomo Executus and Ragnaros the Firelord forms in the same turn, bypassing the power of Ragnaros and not giving him a chance to affect the game.

Defeating the Majordomo Executus form is a challenge in itself, due to his Hero Power summoning a 2 Mana 3/3 every turn. This deck has numerous tools to survive against Majordomo, namely Mind Control Techs, Holy Novas, Deathlords, and Mogu'shan Wardens, to delay the game for as long as possible.

The goal is to stall the game out for as long as possible, using the Priest buff cards to build huge taunts that the opponent cannot push through, until you can gain control of the board. This is fairly easily achieved since Majordomo has 10 Molten Giants in his deck, so if you simply never lower him below 20 health, he will eventually gather a pool of unplayable cards in his hand, allowing you to seize the advantage.

From here, the goal is simply to develop an enormous board, with the eventual goal of killing Majordomo with enough damage left over to deal the 60 neccessary damage to the Ragnaros form in a single turn. This may sound difficult, but is easily achievable using various combinations of Velen's Chosen, Divine Spirit, Power Word: Shield, and Inner Fire.