Concussive Bolt deals 4 damage to target player or planeswalker. Metalcraft — If you control three or more artifacts, creatures controlled by that player or by that planeswalker's controller can't block this turn.
At the beginning of your upkeep, you may look at the top card of your library. You may cast it without paying its mana cost if it's an instant or sorcery spell.
It chews open Mirrodin's husk and feeds on the outpouring of energy.
When Kuldotha Flamefiend enters the battlefield, you may sacrifice an artifact. If you do, Kuldotha Flamefiend deals 4 damage divided as you choose among any number of targets.
Red Sun's Zenith deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead. Shuffle Red Sun's Zenith into its owner's library.