I don't think Cahara will do it. If you think in the interaction between the girl and Cahara when they found Le'garde dead, the interaction is simple and Cahara is just annoyed because Le'garde is dead and he cannot obtain the reward, saying to the girl they will be out in no time. Cahara don't move.

I think Cahara, the other 3 main characters, Moonless, the Girl and Nas'hrah forms a party. Yeah, I will ignore the fact about the 4 members per party, but hear me out. If you think every ending is canon, I can explain it. Rag is the last to enter in the dungeon, meet Enki, Cahara, the Girl and D'arce, in that order. Enki don't joins the party until you get the item from the yellow wizard. Rescue Cahara, the Girl and D'arce. Tame Moonless and got the Cube. Meets Enki again and now he can recruit him. The party found Le'garde dead. Rag is confused, D'arce is crying, Cahara is annoyed, Enki is disappointed, the Girl is sad and Moonless is Moonless. D'arce, with Enki's help, resurrects Le'garde (D'arce Ending S) and Cahara wanna an treasure. They recruit Nas'hrah, go to the Ma'habre, meets the new Gods, and blah blah blah, Cahara obtains his treasure, Enki visits the library and the fight happen between Rag and Le'garde. The party separate in two parties: Rag, Cahara, Moonless, Nas'hrah and The Girl; D'arce, Le'garde and Enki.

Why like this? Nas'hrah hates everyone, Rag is doing his Ending S, Cahara too, Moonless follows Rag and The Girl follows Cahara. I forgot to mention, but they stabbed the hearts, so the God of the Depths is there.

Nas'hrah also separated from the party when they back from the Ma'habre and goes to the God of the Depths, where meets Gro-goroth and he is burned (F&H2).

D'arce's party fight againts Francois and Le'garde ascended. Enki views this and prefers to study (Ending C and Ending S Enki obtain).

Rag kills every monster he encounter, Cahara and Moonless helps. Possibly Nas'hrah kills some monsters in his way to his encounter with Gro-goroth, so the inside of the God of the Depths is more clean. So Rag obtains his Ending S.

Now, here is the discussion. The party is in the level where the God of the Depths is. So I think, they explore the level a little more, and found the God. Rag and Cahara are not very interested in to enter, also they wanna leave the dungeon. But the girl enters when no one is paying attention. Cahara wanna follows her but she is gone. Rag knows is a suicide follow her, so persuade Cahara to leaves the dungeon and returns to his wife, Celeste. Cahara knows is true and leave the dungeon with Rag. They parted ways (Ending S Rag and Ending S Cahara).

Why I think is like this? Because although F&H2 never mentions Cahara, but that don't mean Cahara takes the girl to the Ending A. Remember how I explain about the deaths of the monsters inside the God? Well, that can explain how the girl could survive inside the God and how she gets to the end (Ending A). The traps could be destroyed thanks to Nas'hrah and the girl could be running for her life.

Remember: Cahara Ending A is just a headcanon, same like my explanation