While on some levels its parasitic, a good number of energy cards function great absent any other energy producers
Enchantment Color tag templates(None) Dragon Cultist Commander creatures you own have "At the beginning of your end step, if a source you controlled dealt 5 or more damage this turn, create a 4/4 red Dragon creature token with flying." Legendary Enchantment - Background Color tag templates(None) Flameshadow Conjuring Whenever a nontoken creature you control enters, you may pay
P/T Number 470 Language English Legal Formats Commander, Legacy, Modern, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Pauper, Pioneer, Standard, Timeless Rulings (6/18/2021) Even though you can only activate this as an instant, it is still a mana ability
While there arent many copies available at this price point, there are also a few worse-condition examples, too
In most sets where they have appeared so far, there have been 10 Special Guest cards in total, all at mythic rarity
Crucible of Worlds and Ramunap Excavator allow you to play lands directly from your graveyard
