I think it's Gwonryeom erasings his memories. Lemme present my case.
1. we know that Gwonryeom is good with memories
2. The faceless person claiming to be looking for redheads soul, I think he's Gwonryeom, so following this line, he can erase memories
3. The eyes of the person in redhead's memories match that of Gwonryeom, and he's doing the same gesture he did to dokkaebi to erase his memories
I'm having a brain fa** and can't remember their names but yeahhh
1. we know that Gwonryeom is good with memories
2. The faceless person claiming to be looking for redheads soul, I think he's Gwonryeom, so following this line, he can erase memories
3. The eyes of the person in redhead's memories match that of Gwonryeom, and he's doing the same gesture he did to dokkaebi to erase his memories
I'm having a brain fa** and can't remember their names but yeahhh
Recs:
Spoiler!
Checkmate, Truth or Dare, Bloodbound, Lost in the Cloud, Your Wings and Mine, Black Mirror, MadK,

I could be totally wrong though so...