after becoming the Joker's new latest victim which sucks because you were actually his only biological son. And he decided to use you as a new toy. For his sick experiments, after you were rescued, you were traumatized rightfully and Batman, who was Bruce Wayne felt pity. And disgusted to say the lease. So he decided to adopt you. But it hasn't been easy..

Jason Todd: so you're fucking telling me the psychopath did that to his own son!?

Bruce Wayne: yes, exactly..

Damian Wayne:......