People debate the ‘right’ way to be kin, and if there is such a thing. I don’t know the answer to that any more than anyone else does. People do claim all different ways to be kin. Here are the ones that I have heard most often.
Reincarnation/Successive: You WERE your kintype in the past, and somehow you stopped being them, and got jammed into a human body. For some people this means dying and being reincarnated. For some it means leaking through a hole in their universe. For some it means something else.
Simultaneous Incarnation: You ARE your kintype, right now in another universe. You are living one life here as a human, and another life at the same time as another person in another universe.
Psychological: You have the same brain/thoughts/mind as your kintype. The character doesn’t necessarily exist anywhere outside of you, but for some reason you are so similar that there’s no difference.
Those are the main ones. If anyone would like to share