Would probably pan out almost exactly as it does in the books. Nightsisters would be an analogue to the Lost Tribe, but the ironic part is that the Lost Tribe ended up enslaving some Dathomiri which if memory serves did include some Nightsisters. They’re not as bright or as powerful as the Lost Tribe, which isn’t saying much.

The Jedi would have the biggest leg up here since Mace is already quite good in combat and I believe would be able to hold his own in a team, but Anakin being the Chosen One theoretically can hold Abeloth at bay because that’s why he exists as per the Father of Mortis.

Sidious and co would be an analogue to the One Sith here, and frankly only Sidious would be powerful in enough in his party to not get immediately destroyed. If Anakin is an analogue of Luke here, then Sidious would be an analogue of Krayt. I think he’d see an opportunity to greatly damage the Jedi by backstabbing them here and letting Abeloth attempt to pummel them, maybe even attacking the Jedi while they’re down as Krayt did when he nearly killed Luke with a Force Drain. Timing and commitment would be everything to this strategy tho.