Assimilation Aegis

Two effects that usually eat two cards, welded onto a single three-mana Equipment. The enters trigger is a conditional exile from the Oblivion Ring family: point it at a creature and it stays gone until the Aegis leaves the battlefield. The second ability is where the design turns strange. Attach the Equipment to a creature you control and that creature stops being itself, becoming a copy of the exiled card for as long as the two remain together. You are not stealing the creature so much as wearing it. The equip cost lets you move the identity around: strip the copy off one body and it reverts to whatever it was underneath; bolt it onto another and that one takes on the exiled threat's shape and abilities instead. The tension is that both halves depend on the same object staying on the battlefield. Kill the Aegis and the exiled creature comes home to its owner while your copy snaps back to its original self. That fragility is the price of stapling removal and a copy engine to one permanent: it rewards exiling something with a strong body or a persistent activated or triggered ability, since the copy inherits the printed card's text, and it punishes overcommitting to a single carrier a removal spell can undress. Note that swapping into a copy mid-life does not retrigger enters-the-battlefield effects; the payoff is the ongoing profile, not a fresh arrival. Closer to Sower of Temptation than to a plain O-Ring: control theft dressed as equipment, with a detachable, transferable payoff most steal effects never offer.