Board Thread:General Discussion/@comment-29788596-20160906011125/@comment-32182236-20190805224254

@Mago:I then pointed out how even the claim that LV19 allows Chara to control Frisk is not actually supported by evidence. The slash appears even if we're not using the Real Knife. So if we used another weapon, that slash didn't come from Frisk.. or Frisk's body being controlled by Chara.

Instead, it means Chara is starting to become physical.. A process that is complete after they kill Flowey.

So Frisk is not possessed by Chara at all. Period. Not until after the SOUL exchange.