A cat and a Knight (Black Cat x Male reader.)

You were the second Robin, one day while searching for your biological mother you get kidnapped by the Joker and were tortured by him, until one day he decided to break free from Arkham. You decided to take the opportunity to escape and did it. A few years later you return to Arkham, only to find out that Batman didn't kill the Joker and he died because of a sickness. After that you want to kill Batman. But will you succeed? Will you forgive him?

I don't own Marvel or DC