Hearthpwn

Mulligan: Frost Nova, Mirror Entity, Goldshire Footman, Frostwolf Grunt, Frostbolt

Deck only works if drawing early into Frost Nova against Lorewalker Cho
Do not play Arcane Intellect unless milling yourself for Frost Nova

Fireblast Jeering Crowd midgame to free up room for Lorewalker Cho.
Once Lorewalker Cho is played and enemy field is full, Frost Nova at the beginning of every turn. Otherwise, you might not get a Frost Nova copy back.
This will force Grimstone to play Frost Nova as his only playable card.
Do not play any other spells after Frost Nova if his hand is not full,
Doing so will overload your hand, or Grimstone not playing Frost Nova

Once he reaches full hand, use Fireball or Frostbolt on face.
Otherwise, ping friendly minions to free up your field, or ping face.
Letting your hand exceed 9 will prevent copies of Frost Nova from Grimstone. 

All taunts are there to survive until you draw into Frost Nova.
Deathlord is to hasten Grimstone into fatigue or pull Lorewalker Cho
Use Elven Archer and Ironforge Rifleman same as Fireblast.

I used Unstable Ghoul in place of Voodoo Doctor
That however causes an irremovable minion that can clear his Jeering Crowd
Feel free to replace Sen'jin Shieldmasta for Dancing Swords since he will have a full hand and mana anyways.