If you WANT to say transracial or transspecies or transnational is a thing, by all means do some research and prove it through studies and peer review. Until then, it is unlikely to be recognized the same way that transgender has because it has a lot of supporting evidence.
I want to play a game with you. You're demanding evidence for something that some people have a lot of experience with, but most people don't care to investigate. I wanna do the same thing.
I've decided that fish aren't real. I want you to link a scientific journal article that says fish are real. Not one that presupposes the existence of fish in general, one that asks if fish actually exist and asserts an answer from evidence.
If you can't prove fish are real, why should anyone have to prove otherkin are real?
Buuuuuuuut, if you really want scientific articles on otherkin....
https://czasopisma.uni.lodz.pl/qualit/article/view/8147
Yes, that's how the real world treats male rape victims. This comic is about how fictional misandrists would treat a male robbery victims. Those are two different things. This fiction doesn't make implications about the situation you described.