I count only 29 cards in that deck.
I tried it (with another Asheater for #30). It seems to work well enough. Try the following and see whether you like the modifications:
Mark is Fire
Gravity Pillar x15
Sapphire Charger x6
Colossal Dragon
Otyugh x3
Titan
Graviton Fire Eater x4
The Graviton Fire Eaters are better suited for a supplemental role because they start out doing 0 damage and only slowly build. In the modded deck, the Sapphire Chargers are the main early threat. But while the opponent tries to deal with them, the GFEs are growing.