With a little luck in getting Ysera Awakens from Ysera's end of turn effect and help from Archmage Vargoth and Grave Rune, it's possible to deal 25 damage to everything in a single turn! This is the deck we used to pull it off.

This deck uses a Control Priest shell to buy time and keep you alive until you can assemble the combo. If Ysera dies before giving the Ysera Awakens dream card, you can sometimes generate an extra copy of her with Raise Dead. Draconic Studies will allow you to drop Ysera a turn or two early if things work out well. The setup turn is to play Grave Rune on Archmage Vargoth, allowing him to cast Grave Rune on himself again (thus an empty board other than him is preferred). The following turn, as long as he survived and there's 1 damage on the opponent's side of the board (or the Grave Rune copies are alive at full health/one can be healed by the hero power), casting Ysera Awakens (and only Ysera Awakens as a spell) will ensure that the 4 remaining Vargoths will recast it at the end of the turn for a total of 25 damage to everything in a single turn!

It requires a bit of luck to get the Ysera Awakens, and a bit of luck for Vargoth to survive on board, but it is possible! We've got a gameplay video of pulling off the combo against a Control Priest (with an epic battle of stealing minions back and forth) at https://youtu.be/maWhqN2o3Qc if you'd like to see the deck in action. Now, surviving the combo turn is another challenge... :D Have fun experimenting and have an awesome day!