Board Thread:General Discussion/@comment-29788596-20160906011125/@comment-32182236-20180821222134

"i agree with you there, but. Chara isn't killing for no reason THERE has to be a reason why she is."

I do have an analysis, which includes a possible explanation for their motives. Maybe this will serve as an explanation: https://undertale.wikia.com/wiki/Thread:135687

"well? She wants to erase the whole timeline from where it had started but in this turn she has your soul sold to her, causing frisk to be Soulless on the next Pacifist Run but its 3x Harder since you don't have a soul."

It's actually just as easy. It's just Chara takes over and kills everyone because they have Frisk's SOUL. Just like with Chasriel (what I call the fusion of Chara and Asriel), Chara getting Frisk's SOUL meant that Frisk and Chara split control.

"IF you wanted a reset you would of to get by chara to be able to do so since she is the only with the determination soul you wouldn't die because your soulless it would just mean you don't have a soul to let you be able to reset to your save point or the whole timeline itself."

There's two possibilities here. The former is that Frisk kept their determination from their SOUL, but not their SOUL itself, and the latter is that Chara took both. Under the former possibility, nothing changes until Chara takes over-Flowey was able to come back without a SOUL, after all. Under the latter, Frisk WOULD die without Chara, because you need DT to stay alive after death.

"If you don't have a SOUL, what happens if you-"-Flowey