Anyway the Ralsei being mostly white and black thing is convincing that he is not entirely like other darkners, but I still don't buy the roots thing. He could be some special kind of plant that's had some pure darkness or gaster fuckery, but I think the "he's a manifestation of the prophecy" angle makes more sense
We won't know for sure until something concrete about what he
is is confirmed. Really, we just keep getting confirmation for what he
isn't.
We know he's not secretly being carried by Kris, we know that whatever he
is can't really be carried around (Otherwise he could've been carried around to 'see' the festival.
And we know he's probably not Kris' old monster horn headband either, as that shouldn't have any sort of means to move from Dark World to Dark World.
Though I suppose it's possible that whatever Ralsei is, his actual object form is really in the Shelter, and the darkness in there is esoteric enough that he can appear in other Dark Worlds? (This would keep headband theory alive, if the Shelter is involved in the INCIDENT and Kris was there on that day and ended up dropping his monster horns?) (This lil' goat nigga is far too esoteric for my liking, though him being Kris' equivalent to what Flowery was with Asgore would be funny, also, if he was Kris' monster horns, and Dark Worlds
are based originally on Kris and Noelle's imagination games, he'd know a lot about them, too. )
Also, you wanna know what really fucking feels like missed potential?
Toby Fox has had Laura Shigihara work on Deltarune songs before (she literally fucking sings Don't Forget), but he didn't get her to sing the vocal parts of Flower Man? Come the fuck on, Robert!