He has been in a hiatus for a decade and realizes the monster he is in that moment and reverting back to his former self the moment afterwards "Hello, Dexter Morgan," and ends up fully become the monster by the end, not even realizing it until his son sees him for who he really is.
At least he is very carefully choosing victims one to one,he doesn't kill cowardly, he's a serial killer. Even if we know killing is a sin and killing is wrong but he kills the bad people. There's many bad people at Israel government right now,if we had a Dexter, we'd make justice there too. Anyways, Dexter is a hero of the people,smart, genius, psycho sexy. .handsome and letal. He's sexy