Ideas for new faction?

I know, I know… They haven't announced any new faction or anything, I'm just curious.
What's left to explore in the Witcher universe that could introduce a whole new faction instead of current faction support?

I mean, there was Ofir but they introduced them as neutrals, now what's left?
Vodyanoi are out there but I highly doubt they can make a whole new faction out of it instead of just throwing them into monsters just like Dagon.

If they ever plan to introduce a new faction, it may be headcanon and completely based on CDPR's view of the Witcher world.

Or is there any other region that I am missing?

Edit:

Lecture comprehension guys, I'm asking for new faction ideas, not saying that it's needed or that they should do it or anything like that.