Scene: After their Atlas adventures Team RWBYJNPRQOTZM visits the Pine Farm on their way to Vacuo. Oscar explains the basics of the situation to his aunt as he apologizes for leaving.
Aunt Emma: So this man bonded with your soul so he could keep fighting this immortal evil? That's why you left without even saying good bye?
Oscar: I cannot apologize enough for that. I was afraid if you tried to stop me it'd work. I love you and owe you so much but there are people who need me.
Emma: I'm happy you found a calling Oscar, I just wish you were able to tell me to my face instead of only leaving a note. And now you tell me you're merging with this guy? How does that even work?
Oscar: Do... do you want to talk to him? *she nods and so Oscar passes control to Ozpin*
Ozpin: Hello Miss Pine, I am professor Ozpin. It's a pleasure to meet you.
Emma: That is NOT my nephew!
Ozpin: I understand this is difficult for you. I truly do. What Oscar told you is accurate, our minds and souls are merging. However this does not mean that he will be replaced by me. Far from it, in time I will begin to be influenced by his personality until I begin to lose my individuality. By the time the merger is complete Oscar will have complete access to not only my own memories but those of all who came before myself as well as complete control of our magic. Whether or not the memories change him is up to him and him alone. He may adopt some of my physical mannerisms but that is purely muscle memory.
Emma: You're sure?
Ozpin: I went through the same experience. I swear to you on all my lives Oscar will remain Oscar.
Emma: Thank you. But this is still creepy.
Ozpin: I fully understand *Ozpin passes control back to Oscar*
Oscar: I was worried about it for a while but I trust him.
Emma: And I trust you.