Thaddius Priest Deck for Heroic
Why using Priest? Because of Shadow Word: Death and healing.
The key cards for this fight are Shadow Word: Death (in order to get rid of one of the two initial enemy minions), Tinkmaster Overspark (to turn a 4/7 or 7/4 into a 1/1).
The small taunts, Goldshire Footman, 2x Neruabian Egg will become a 4/4 from Thaddius’ ability.
2x Unstable Ghoul and Sunfury Protector for more taunts. Same with 2x Ancient Watcher. This fight is about surviving.
Other than that, the basic priest mechanic with buffing cards, in our case, the 2x Mogu’shan Warden.
If you manage to get rid of the two initial enemy minions, you have a good chance.