Imagine...
"Oswald!! This is nuts. Do you want Fish to catch us...?" He simply smiled, grabbing you by the hand.

"I don't care if she does (Y/N), I can't let her just use me anymore...." You smiled a little. You knew your brother was perfectly able to be his own boss. He has the leadership, the wit, the charisma. And definitely the power. He's head strong. And he's a great big brother.

Oswald and your mother Gertrude are the only family you got. You used to think Fish was as well. But she really pushes Oswald constantly, treating him like some object she can just use whenever she wants.

"Just... be careful. I will admit though, this is pretty fun..." He looked down at you, giving you a huge grin. Going against Fish actually feels pretty good. You can certainly see a future where Oswald rules Gotham....