You're Vastaya! And you're Vastaya! EVERYONE IS VASTAYA
Seriously, why is this brand new blanket term being applied to any champion that has some kind of animal power and/or physical feature?
I was listening to the Xayah interactions and she has quite a few with the other Vastaya. For those who aren't aware, Vastaya are this order or class (not necessarily a species according to this in-universe journal entry, but instead a more general taxonomic classification) that are combinations of human and one or more animals, very chimeric in nature. The new champions' lore is implied to be very reliant on their heritage as Vastaya, particularly Xayah who is a rebel for their cause (whatever that will entail, lore details to follow). Both Rakan and Xayah interact with the Vastaya, giving us a good indication of who else falls under this term.
Literally, every Champion that has qualities of an animal or turns into an animal that isn't already classified as a Yordle: Vastaya. Every single one of them.
With some Champions (particularly 
) whose origins are unexplained, this makes sense. And while with 
Ahri in particular I thought her origin story already sufficiently explained, Xayah and Rakan were obviously designed to look a lot like Ahri and are even from the same region, Ionia. My problem comes with the fact that it feels like it sort of waters down a lot of Champion's backstories. It was a detail that either didn't need explaining or isn't a satisfying explanation.
Just to give you an idea, I'll list the Champs in question and briefly talk about why I think this is a silly blanket term that--while fine on Rakan and Xayah who were written with this term in mind--doesn't contribute to other Champions' lore in a meaningful way:
Ahri - explained above
Nami - Her species already had a name: the Marai. What does it add by knowing the Marai are Vastaya as well? I didn't think we needed explained why there was a race of mermaids living in the ocean: we just figured they existed and that was enough. Adds nothing to Nami's narrative.
Nidalee - her place on this list implies a retcon, either that or she became a Vastaya, formerly human. Either way, again, I think this is a case of "this was never a question we were asking". Nidalee can turn into a cougar because she was raised in the dangerous, magical jungle. We didn't need a taxonomic classification to explain that.
Rengar - Probably the only one that makes sense, given (if I remember correctly) he was found and raised by a regular human guy and doesn't really know his own origins. That said, Rengar's story works surprisingly well without knowing what he is. He's the best hunter, the lion visuals are just fun champion design.
Swain - Another one that needed the origin of his powers explained but uh...if it turns out it's just in his blood I'm going to be a little disappointed. Swain is a tactical genius, I figure he tricked some hag into transferring her powers or something, or befriended his raven Beatrice with his intellect. I don't know, something befitting of the Master Tactician.
Udyr - I don't know why he's even on this list, considering I felt his powers were already sufficiently explained. I always thought Udyr was about connecting with nature and animals on a spiritual level, mastering his powers by meditation and study. Being Vastaya or having Vastaya blood or whatever sort of ruins that.
Wukong - Again, another one where this is fine, but didn't need an explanation. They just wanted to be thorough, I guess and include every animal possible.
Notable exceptions here are Anivia, Elise and...I think I'm missing one. But look at that list! That's almost every champion with a somewhat human appearance and other animal characteristics. The reason I don't like the Vastaya term is that it makes these champs feel a little same-y. Like, before, Nami and Nidalee were very distinct characters that you would never confuse. But now oh look, they belong to the same species. And yeah, the journal entry explains that it's more like a larger classification like an order or class, but who else other than the lore nuts (like me) is going to read that? Who is going to care?
I will leave with the statement that we don't know all the facts, Xayah and Rakan's lores have not been released in full yet and something may change my mind. But for the time being, I am a little baffled.
and Xayah's 
release. I'm not really sure how their lore would have worked without it. I suppose they would have done some cheesy story about how they were once one great being who was torn apart, and different attributes were distributed among the two, now they can't fly without each other yada yada yada. But I think this makes more sense. The fact that they made two characters who are both the same kind of creature means that they can either give that weird explination, or they can reveal that vastaya exist and that there are more of them out there.
