Talk:Neutral Route/@comment-26889480-20160506133927/@comment-27555277-20160506135727

If you want to be technical here, that would be impossible because there's no way to activate genocide beyond the ruins if you leave Toriel alive. There is no way to enable the kill count and it won't register as you eventually killing everyone in an area--not to mention some enemies simply cannot be killed outside of genocide (ie: the Mad/Glad dummy, Sans).

That being said, if you were to try and do that, the likely result would probably be the ending where Toriel returns to the ruins to allow anarchy to rule, Sans stops by regularly to bring her books and stuff like that, tells you never to come back, so on so forth.

The theory may stem from the fact that there's an extra death image for Toriel in the game's data, implying that she may have been planned to possibly kill herself under certain circumstances. This does on occur in game though, and the fact that it was a full body battle image suggests it would be during your fight, not after you leave the Underground.