Creature ramp: Solemn Simulacrum, Sakura-Tribe Elder, Wood Elves, etc
If you Enchant either Monolith, you can tap to add mana, then pay two less mana to untap the Monolith thanks to Power Artifact, tap for more mana, and repeat the process
Access to 6 of MTGs most iconic spells is incredibly powerful, and while only Braingeyser and Regrowth see consistent play in the format (though Black Lotus absolutely would if it was legal), Terror, Disenchant, and Shivan Dragon can all still be very handy
Etali, Primal Conqueror is the biggest and scariest of them, starting off as a 7/7 trample threat that generates impressive value
This makes infect one of the quickest and nastiest ways to win a game of Commander
During each of your turns, you can play a land and cast a permanent spell of each permanent type from your graveyard