Damian Wayne was Robin. Son of Batman and Talia Al Ghul. Loved and taught what it was to be a hero. At least that's the story you're familiar with. In this world. Damian is an outcast. Disowned by Bruce and Talia not having known or maybe even cared. He wandered the streets for a while before a certain cat took him in. Taching him her ways and turning him into the perfect little sidekick.

(Yes Damian is 18 in this as per the rules)