They're equally satisfied by an artifact you sacrificed to pay a cost, a creature you controlled that was destroyed by Murder, or an enchantment you returned to your hand with Leave in the Dust
A: It's kind of a weird thing to give up, to be honest, but if you're familiar with the old card Rock Jockey, it'll help
Did you kill or exile him
And he's only said Standard is most popular online when asked about Arena (as far as I could find, anyway)
Maybe this is the place for all those weird Strixhaven archaeology cards like Lorehold Excavation
For the purposes of this list, Im sticking to cards in greens color identity, so every green card here is fine with your mono-green commander in EDH