How would one write a Symbiote persona (host!user or symbiote!user) without just explaining the entire (spoilers) Klyntar race?

Because like

I really, REALLY want to make a host!user persona using my symbiote OC who I've not gotten the chance to fully flesh out yet

Also

The Roaring Knight? More like The Roaring Fraud with how easy it is nohit him/her/them. (I say this whilst having not even beaten him/her/them yet)