Not to be confused with the Worst endings in the older versions of Nightmare Beginning.
Old Exetior walks through the Master Emerald Shrine past the first Trinity and Metal Sonic, who have all been defeated. He jumps onto the Master Emerald, obtains its power, and it zooms in onto his face before it blacks out. It then shows red text saying, "Exetior killed off Sonic and his friends, and absorbed the master-emeralds power, with nobody to stop his wrath. Mobius will be doomed to be filled with the tormented souls of its inhabitants."