The Mana Rig
[Dominaria United Commander]

Whenever you cast a multicolored spell, create a tapped Powerstone token. (It's an artifact with “{T}, Add {C}. This mana can't be spent to cast a nonartifact spell.”)

{X}{X}{X}, {T}: 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.