Most have nearly all their nonland reprints in artifacts, enchantments, and other noncreature spells
There are cards that convert your energy to tokens and some that convert it to damage
If it would be destroyed that turn by damage or an ability, instead of being destroyed it is tapped, the damage it took is reset and it is removed from combat
Add Underworld Breach into the mix, and you can keep casting Wheel of Fortune over and over, netting tons of Treasures in the process
Having all your nonland cards be creatures isn't the greatest plan, but if you're into weird decks and you're in green and black, I can see this being a fun, janky, casual project and maybe a good deck for players just starting to learn
A player loses the game after having been dealt 21 damage from one of them, not from both of them combined