you can just taste the "it was all a dream/hallucination" twist coming up, and the taste is sour. Not because it's been fermented, but because it's so old that it's started to go bad. Seriously, the items connected to the "outside world" meaning outside his hallucinations that allowed him to access his phone are probably the only weapons his subconscious will allow him to use to kill the imaginary family. Cool foreshadowing with the sharpened mailbox post ig, but if it's obvious that everything's a hallucination the story kind of loses its stakes, since at that point we're being asked to care about the mental well-being of a serial killer and that's kinda a hard ask.