I think we'll ride Lunala in UM and Solgaleo in US.

Just like BW2, we're gonna get the box legendary, which is necrozma.
So how are we supposed to fight Sol-Necrozma with Solgaleo if he ate it?
Unless we'll not find ourselves in a scenario where he absorbs the nebula before we fight him.

Point is, in SM the male protagonist is Sun and the female protag is Moon, why are we seeing them ride the other legendary in pic related?
Just like we've seed in the japanese trailer lunala fight with necrozma on the altar with the protagonist being Ray (Sun).

I'm struggling to decide which version to play, help me with theorycraft 'n shiet.