Board Thread:General Discussion/@comment-30088034-20170211001105/@comment-32182236-20180608111747

"Also, the killing! It isn’t confirmed that it was Chara who killed Flowey, Sans, and Asgore upon that assumption. It could have been Frisk..."

We did not press Fight for Flowey, Sans, or Asgore. Well, we did for Sans, but we didn't make the final strike. Plus, in my Geno run, I'd want to kill Flowey in one hit like everyone else, not multiple!

Since Frisk is the player, and the player didn't kill them, then FRISK didn't kill them. That leaves Chara.