The name of the game is stall + draw. You can typically use many of the OTK damage pieces for removal as needed. I particularly like Living Roots for this because of the extra 1/1 Saplings spawned after completing the quest. The final combo is Aviana + Innervate + Kun the Forgotten King + Malygos + Sathrovarr + 2xMalygos. This gives +15 damage to each spell, typically only requiring 2 Moonfires to finish the opponent.

Max damage if you can pull it off is 86 with Wrath puling the 4th Malygos into + 2xLiving Roots(22) + 2xMoonfire(21) or 85 with Swipe(19) + 2xLiving Roots(17) + 2xMoonfire(16).