In Breaking Bad, Badger notes that even Darth Vader had responsibilities to the Death Star.
His point is that even evil people have responsibilities and perhaps even a code that they abide by to live their life.
For example, take Dexter Morgan. In Dexter, he is a serial killer. However, he only goes after criminals who haven’t gotten caught. He takes his victims by surprise, injects them with a small amount of etorphine to immobilize them and then binds them to a table, using plastic wrap. His crime scenes leave no trace, as he learned how to leave behind no evidence. Being a forensic technician has helped him with that, too. He then wakes them up with smelling salts, shows them images of their victims and then kills them. He then dismembers their bodies and dumps them into the ocean.
To Dexter, he has a responsibility. In his mind, all the criminals who got away with murder deserve a place at his table, so to speak. Because he has this insatiable need to kill, he has channeled the urge to do good in his mind.
We learn early in the series that his adoptive father, Harry, believed that Dexter had the impulse to kill as a young boy. So, he taught him a code to live by when it came to killing. Only kill the bad guys who you know for sure are bad.
