so major spoilers here but:
from the way the rope that holds the camera on echo slowly becoming noose like i think remnant is echos past self since it is implied it is a time loop
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Spoilers BTW
I think it's a past version, or another wish entirely because when the remnant talks to Sissel he said he came from the MC's depression, and I think that He is depressed due to his parents and their relationship towards him and each other and that the MC's wish was to die or something along those lines