Legendary Universewalker — Byode
+2: Mill three cards, then return any number of cards from different Universes milled this way from your graveyard to your hand.
-X: Choose a Universe you haven't chosen this way this game. You may cast a spell from that Universe with mana value X or less from your hand without paying its mana cost.
Byode, Inverse Sun can be your commander.
Your deck can include Universes Beyond cards of any color identity.