I also would like to know why other humans have the collar thingy, does that mean there are other god-like beings? Then is that how the batsu reproduce?
idrk but i think its some sort of ownership or smth. like it dictates/proof of one's standing in life? i was thinking something similar to Royal Servant but idk i dont think other "normal" people have power.
so if Rei was the first human-batsu hybrid then how have batsu's been able to reproduce? also didn't seem like there were any others