On its own, Medomai the Ageless has some exceptional abilities
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Notes and Rules Information for Icon of Ancestry: You must choose an existing creature type, such as Vampire or Warrior
Right now I have it in so that I have something good to return with The Mending of Dominaria, but maybe a better plan is to use Bone Dragon and not The Mending of Dominaria, either just relying on Devious Cover-Up or possibly using Bone Dragon to sculpt your graveyard for Gaeas Blessing, though that sounds like the kind of late-game nonsense that will never actually come up, whereas Gaeas Blessing messing up your Bone Dragon will come up
My guess would be that it'll likely be Common and Uncommon cards like the Bidoof above, as I don't think they'd dare do this to, say, a Radiant Charizard
Creatures (5) Planeswalkers (6) Lands (19) Spells (30) Miracles has been one of the best decks in Legacy since Terminus was printed