In the pinch of the end game, the flexibility to not cast it or target your opponent makes this loads better than some of black's most famous spells
SR Super Rare Blaze Fenix, the Burning Bombardment Bird X FIRE Level 8 [ PyroFusionEffect ] ATK 2800 DEF 2300 1 Machine-Type monster + 1 Pyro-Type monster Once per turn, during your Main Phase: You can inflict 300 damage to your opponent for each card on the field
1 2 Professor Oak Interview
Take out the cost-cheating cards like Aetherplasm and Belbe's Portal, and then maybe consider shaving off stuff like Cabal Coffers, Crypt Ghast, and Bubbling Muck until your deck is at the speed that you're aiming for
Furthermore, Energy Cards come in several elemental types: Fire, Water, Grass, Lightning, Fighting, Psychic, Dark, Metal, Colorless, and a few special varieties that buck the rules and do something unique instead
Loxi: It's a fun idea but I'm not super sold on the whole "can't attack half the time" scenario if you want this as a commander