HELLO? IS THIS FUCK WEB?

Before I start, some prefaces: this involves a lot of head-canon shenanigans, so please see this as an AU. My lore is, as always, subjected to change based on my whims.

So, in canon, NE-a parasites function by cutting off + entirely replacing the host’s brain with itself. Basically piloting the body like a mech suit. But, (hand waves the science. I mean… it is Resi) let’s just say that since Deerstalker have a human host instead of a Tyrant host, its body was too fragile to survive the brain severance. So the parasite was forced to adapt, for survival, to meld with the human brain instead of replacing it. This meant that Deerstalker is neither human nor parasite but a secret third thing! An amalgamation of both!

Most of the time Deerstalker recognises itself and functions behaviourally as a singular entity. Very rarely, a desynchronisation would happen (especially if it thinks too hard about its existential implications) and the brain would suddenly recognise itself as two distinct entities. At which point the human body would try to purge the parasite as malicious foreign matter, and the parasite would try its best to gain the upper hand of its consciousness without killing the host. Overall, an incredibly excruciating experience where neither prevails. Eventually the parasite vs host would find an equilibrium, and things return to “normal” again. 

Which is why Deerstalker has such an apathetic personality/reaction towards the tragedy of its own creation - it’s trying to not think about it too much to avoid the parasite-host desynchronisation. Though the parasite - with no grasp of human morals - sort of views Deerstalker's creation as an overall positive even if the incident was soul shatteringly unbearable for the human host.

Now the parasite-host memories are all muddled together. Deerstalker has vague memories of a human childhood, but also memories of being grown in a lab. It also distinctly remembers the human host’s direct involvement in the development of the parasite self as an Umbrella scientist (in a weird ‘I physically created myself’ way). The memories and associated feelings are too complicated to navigate so it has compartmentalised it and outwardly expresses it as uncaring/indifferent. 

And this indifference makes Handler Dayus so frustrated at times because he’s all: "how could you not care about what they’ve done to you!?". Which speak numbers on the differences between how Deerstalker perceives itself (weird secret third thing that's more than the sum of its parts) vs how Dayus perceives* it (a human who got infected). This difference in perception is one of the main conflicts between the pair <3