The Brothers' War

Arms Race | Enchantment | | {3}{R}: You may put an artifact card from your hand onto the battlefield. That artifact gains haste. Sacrifice it at the beginning of the next end step. | Leesha Hannigan

Visions of Phyrexia | Enchantment | | At the beginning of your upkeep, exile the top card of your library. You may play that card this turn. At the beginning of your end step, if you didn't play a card from exile this turn, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.") | Dominik Mayer