Gotham now

His name Tark Digger aka Big D is working in Gotham

The Wayne industries.

He remembers his family talking about the Wayne family

After the wayne got murdered he went through life and he slowly trained how to fight. Ever since Martha and DR. Thomas Wayne, something broke in Gotham and now organized crime has run rampage through Gotham.

Over the years though Tark Digger trained hard on the streets of Gotham.

He didn't have formal combat training but he learned the basics of how to fight : Gotham style and over time learned how to hold and use a gun and knife and some other weapons.