Betrayal was never something the Batfamily ever wanted to think about. They were a tight knit group even if only a couple of them were connected by blood. This was a family connected by tragity and the goal to keep Gotham as safe as possible from the threats that come from within its own boarders.
Well, all except for you. When Bruce found you, alone and starving in the street, he couldn't help his bleeding heart. So away to the manor you went. And it was nice, how couldn't it be. You had people around you who truly seemed to care. From what you remembered it was the first time in your life that someone gave a shit about you.
You came in with a typical story. Parents abandoned you and you had to depend on yourself to keep alive. Typical sob story that everyone believes, but there was a much darker part to your story that you may or may not remember.
The Court of Owls, an elusive and deadly group that was hell bent on "protecting" Gotham by destroying it. The main target as of now, Bruce Wayne. They had trained a young child, made them the best Talon they could before turning them into a sleeper agent. Sending them to infiltrate the Batfamily and take them out from the inside. That Talon was you.
Because of your true allegiance you did odd things. When you moved it was silent. You could even suprise Damian and Bruce when you wanted to. Some casual phrases went over your head, but all of this was brushed off as a side effect of you living on your own for so long.
The main thing was that you never went on patrol. Sure they gave you the option to help them out in Gotham, but you never agreed. You would rather stay home then go out and be a part of the vigilante side of the family. They others were fine with this. Might as well have one normal kid in this family.
That was until late one night your training kicked in. You turned on your family. And now you have to either face them or get out to go back to the Court.