Seems relatively balanced, though it would be devastating on the field with some heavy armors and rage potions/elixirs in the mix. However, considering that it is a high cost, and would require a build with only these cards and fire pillars/towers and earth mark to make it consistant, I see no problem whatsoever with this being too OP, for even with such combos, a few CC spells/skills will easily cut through this like tissue. I like the idea by the way.
