S1, E5: When Isana sends Yumeji and Merry to the local mall to do some grocery shopping, the trip instead turns into an encounter with the most powerful Dream Demon they’ve met yet. But Engi ThreePiece isn’t your typical Dream Demon. She’s a Dream Demon with a mission - a mission that sounds suspiciously like what Merry is attempting to do. Is she really a human-enslaving monster? Or an, as yet, unrecognized ally? Only time will tell, but it may be running out.