So... Is he witnessing the destruction that happened in Chapter 1 but from a different POV or something along those lines? Like he's on the astral plane layer of Japan, can partially interact with reality, in a weird time vacuum of the events that led to his death that isekai'd him in the first place, or is it just a replica?
Also, guess the person that they're going to go rescue will just need to endure a bit more torture while he levels up.