Board Thread:General Discussion/@comment-4504826-20160516034744/@comment-30708811-20171218053955

I think everyone who is saying that determination in Asriel and Chara being the problem were right.

You need determination to save - a specific amount of it, which monsters don't have (except Flowey, since Alphys was testing what happens if you inject human determination into flowers)

Maybe Chara had that much once upon a long time ago (having the Determination soul) or just never cared enough to use it. She hated humanity and wanted them to suffer (maybe even herself if resetting never occured while she was snacking on buttercups).