The Mana Rig (Extended Art) #80

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.") XXX, 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.