If you're a therian or otherkin or, maybe there's another term I don't know about, I wanna hear what defines that for you! My understanding of it seems to be a little different from how I personally feel about my identity, but perhaps I just don't have an accurate impression. so ye, I am curious c: (I'm also not that knowledgeable about some things so you may have to bear with some silly ignorance)
Logan's otherkin, and I suppose we all are, because for us it means that our souls aren't human. Logan knows deep down inside that he is an Umbreon, and only an Umbreon, regardless of... the host body that we're all stuck inside.
(I find it a bit weird that we have a special term just to mean we're something other than human — since when has that been the default? — but we identify by it anyway~)
Anyway, he's otherkin because he fully identifies as an Umbreon, he expresses himself as an Umbreon, he imagines himself as an Umbreon (his headspace body is an Umbreon), and so on. He is just completely the mind and soul of an Umbreon and not a human.
We all are that way, so we're technically all otherkin, but he's the one who identifies by it the most because he used to be a singlet and also our host, so he's the one who is most differentiated by being nonhuman.
I believe therian is a specific type of otherkin that means you identify as a "real-world" animal ("real-world" meaning part of external reality). None of us are therians, we're all Pokémon.