....Oh yeah
We NEVER saw the content of Rubia's scenario (which is S -rank, where as Rena here is B)
Considering there's a scenario after this, I'm guessing this'll go either.
1. She betrays him.
1.a On her own will - She rises up enough in position that she think 'it's time to tie my loose ends' , like say she's an assistant branch manager (which means the next scenario doesn't trigger yet)
1.b Forced into a choice, she chose to betray - Same thing as above, assistant manager position obtained, but the branch manager then decide to go with her into the dungeon, run into Skelly Bro, and between trying to silence the branch manager or act like she doesn't know skelly, she chose betrayal.
2. He succeeds, which will mainly be to show us the readers how these scenarios work.
Given the 3rd warning point that she can betray regardless of how close they get, she might betray him during the next scenario, "assistant of the shadow"
That said, I get a feeling Rubia's scenario will end up being key (or one of the keys) to ensuring Succubus's safety.
Like, say, by making Rubia the lord of the town, he's able to have her stamp down on those crusaders' corrupted religion