Iron Bane Forge

{4}{t}: Destroy target artifact, Choose one -
Add colorless mana equal to twice the destroyed artifacts converted mana cost, Create a X/X Slag Token where X is destroyed artifacts converted mana cost with trample.
At the beginning of your upkeep, you may pay {2}. If you do, untap Iron Bane Forge.
Iron Bane Forge doesn’t untap during your untap step.