From LEGO Batman Wiki
Deathstroke is a Super Heroes minifigure who appears in the 3DS version of LEGO Batman 2: DC Super Heroes.
Deathstroke has a blue head with orange patch on it. He has a blue torso decorated with an ammo belt over muscles. He has blue arms and orange gloves. He has orange hips and legs.
Slade Wilson was originally a soldier in the US army who was chosen to become part of an experimental super-soldier project, which he gained enhanced strength, agility, and intelligence as a result of. He took the name "Deathstroke" and went on to become the greatest mercenary in the world. He is sometimes seen fighting along Two-Face. He is usually seen fighting the Teen Titans (which has consisted of Robin I, Cyborg, Supergirl, and others).
In the Video Games
Deathstroke has only appeared so far on the portable version of LEGO Batman 2: DC Super Heroes as a playable character. He is made available for Free Play after completing the Gotham Metro Justice League mission.