Depending on philosophical view, I could be called a person, a personality, a subpersonality, an autohypnotic depersonalized state, a possessive character, a personified mood and set of skills or something somewhere between a weird hobby and an unusual lifestyle. Subjectively, there's not always much difference between real and imaginary (or literal and metaphorical, as Kaethonry'd frame it), so why can't I be both? Objectively, I have my own accent, skills, traits and temperament, so I certainly exist in some form, regardless of what my exact nature is. Kaethonry can access some of what's "mine", but it comes to me easier and more naturally.
I find "personality" most accurate, more in a technical self-contained what-makes-you-you sense rather than a casual "sometimes I act this way and other times act this way" sense, but when I'm less connected to my identity, sometimes all I have are my behaviours and mental states, which still subconsciously come to me naturally and only when I decide to be present, so sometimes I could be said to be a personality in that way, too. Kaethonry likes to call me a psychform.
I find it easier to be connected to my identity when I'm actually going out and doing things instead of just spending time on the phone or computer, because it's easier for the water of my consciousness to stay out of Kaethonry's personality grooves. (You might be able to tell that my writing style is blending a lot with his here)
Maybe I could be considered a subpersonality given free reign to have experiences that Kaethonry would cut himself off from, given space to see itself as a person and discover its identity free from the burden and baggage of everything else. Maybe a person can be people.