Razorgore, followed by Vaelastrasz. Those 2 cards just win you the game most of the time if you draw them early.
EDIT: I am sorry, i was in Brawl mode. In constructed Vaelstrasz would lose some value because of BGH but I still vote for Razorgore. (Yes he has no impact while he is played but 4/12 for 6 mana with immense snowball potential is still amazing)
EDIT 2: This is my last edit^^ My first answer was just about Brawling mode, my second after I realised that I rushed and now my answer after I thought about it: Whirling Ash. This card would Tempo everyone out of controll. Nobody can deal with the 5 health that early in the game and this card is great in trading too.
Vote & Discuss!
The answer may well be different to which cards are better in the Tavern Brawl itself due to Nefarion starting on 5 mana...
Card details below :
MOIRA SHOULD COST 3 for a 4/3 with deathrattle : Summon Emperor Thaurissan
Living Lava SHOULD COST 2 MANA
Son of the Flame SHOULD COST 3 MANA
Whirling Ash SHOULD COST 2 MANA
Razorgore, followed by Vaelastrasz. Those 2 cards just win you the game most of the time if you draw them early.
EDIT: I am sorry, i was in Brawl mode. In constructed Vaelstrasz would lose some value because of BGH but I still vote for Razorgore. (Yes he has no impact while he is played but 4/12 for 6 mana with immense snowball potential is still amazing)
EDIT 2: This is my last edit^^ My first answer was just about Brawling mode, my second after I realised that I rushed and now my answer after I thought about it: Whirling Ash. This card would Tempo everyone out of controll. Nobody can deal with the 5 health that early in the game and this card is great in trading too.
Who can take your trash out?
Stomp it down for you?
Shake the plastic bag
and do the twisty thingy, too?
Yeah - I reckon that Vaelstrasz might not be the answer although its potential to enable game-breaking combo turns is noteworthy.
The real answer might just be Living Lava as a 2-drop 6/6 Taunt!
I've voted for High Justice Grimstone, though.