This isnt a possession. This is him remembering his past life late and his outlook and personality being affected by that. I can understand why you are confused since he keeps referring to his past in third person as if that wasnt him.
I don't understand why the MC is treating his past like it didn't happen to him. This isn't a transmigration or possession, this is reincarnation where he just remembered his past life late but he keeps mentioning his past in third person as if it didn't involve him. It's not as if he lived that...
And now i remember why I stopped reading the novel version. That collar gag wasn't funny the first time but the author beats the joke to death by using it all the time and it gets annoying FAST.
I thought that too but the "him" pronoun thing from last chapter is a staple mtl translation mistake. A human translation wouldnt normally make that mistake. Many of the other mistakes I have seen in the last 2 chapters or so are also the typical mistakes made by MTL translations.
Intentionally androgynous with those boobs? She's clearly just a typical tomboy character. A female using the masculine "I" (Boku) to emphasize being a tomboy. This is hardly anything new in anime culture. Also most of the dialogue in Japanese probably doesn't use pronouns at all given how the...
Or maybe the others have got her covered? I find it odd he got there before the rest of the team who figured it out before they even informed 001. Maybe this is a trap to capture 003 alive.