þ absorbs the rest of O's deteriorated body and... Oh. Their horn is dulled. OR also decides it's best to leave the fight before it gets worse. The failed collision of Z's halves sends Overseer O flying back onto the battlefield, temporarily knocking the latter out cold. As Z's halves are about to drift away, Fourth Wall Y acts fast and makes it so that Z's back in one piece, without a devastating explosion. The only problem is Z's axis being off.
c2a