marvin mtg card - magewright's stone Murderous Mimic has all activated abilities of creatures you control that dont have the same name as this creature. Marvin, Murderous Mimic | Duskmourn:

Choices made for permanents as they entered the battlefield are remembered even after they phase in

Myr Reservoir, as mentioned above, is a great repeatable grave recursion tool for Myr tribal

Even in decks that arent specifically attacking graveyards, the sheer flexibility of choosing the best available body to copy means he rarely whiffs, and a 4/4 with an upgraded statline for four mana is already a fine rate on its own

The TOP White burn spell in Commander has to be Comeuppance

Yes, you lose some life every turn, but The One Ring is also indestructible, making it extremely difficult for your opponents to interact with, and you really should have some bounce spells to maximise the potential of The One Ring (and to not lose too much life)