The Mana Rig (DMC-028) - Dominaria United Commander

Whenever you cast a multicolored spell, create a tapped Powerstone token. (It's an artifact with ": Add . This mana can't be spent to cast a nonartifact spell.")
, : Look at the top X cards of your library. Put up to two of them into your hand and the rest on the bottom of your library in a random order.