That would be possible if they had access to the void, and even so, considering how glitchy frisk is, entering the void wouldn’t let him go back in one piece and instead it would probably kill him, thus ending the timeline
That would be possible if they had access to the void, and even so, considering how glitchy frisk is, entering the void wouldn’t let him go back in one piece and instead it would probably kill him, thus ending the timeline