Quicksilver, Shifting Slime

When Quicksilver, Shifting Slime enters the battlefield, search target player's library for an artifact card and exile it. Quicksilver, Shifting Slime becomes a copy of that card except it's still legendary, its name is still Quicksilver, Shifting Slime, and it gains "When this permanent leaves the battlefield, shuffle all cards exiled with it into their owner's libraries."