we know that there is 5 main li (which mean solo ending in addition of two ending with two specific girl and a Harem ending ), Talitha,Esther,Lyra,Nevaeha + another one he didnt reveal because if would spoil the story (and he said that in june 2023 so the two more likely candidate are Luneira who just appeared at that time so giving that for now she's bound to the sword, it could spoil the story to reveal it was her , or some people believe it's Leliana because she's a vampire but no so sure personnaly because just saying her name wouldnt spoil about that anyway.
What i found interesting is the two names root , Luneira is tied to the moon "daughter of the moon", when if we dont know the name of the other elven girl, Esther have two interesting meaning, star,like the sun, but also 'hide' "conceal", which directly connect to Amaris plan with the veil, so it's probably not just Esther who's necessary and i could totaly see mc sword needed in this to kill Esther with it in order to conceal the light of the stun with the veil ,who could be some kind of permanent eclipse (it kind of make me think of skyrim with the vampire dlc )
So Luneira and the other elven girl could be from two different clan , like sun elf and moon elf, which could bring maybe some rivalry/antagonism between the two who knows.
Or maybe that Luneira wont like much and mistrust Esther at first (especialy if she's connected to vampire since Amaric is her uncle ) but i dont believe it would be something major if it happen and it could be funny to see some cat fight between elven girl eventualy ^^