10 Batmen Who Aren't Bruce Wayne

In the one-shot story Batman 666, we get a glimpse of a possible future where Bruce Wayne is killed, leaving his genetically modified, super assassin, possibly demonic son Damian, as Batman. Damian, the son of Bruce and Bruce’s some-time lover/all-the-time psychopath, Talia Al-Ghul, must toe the line of hero and villain, attempting to deny his own dark nature while respecting his father's vision of justice.

It seems Bruce was the softie in the Wayne clan, as again, Damian's methods are far more brutal than his fathers, having broken his dad's "no killing" rule multiple times. This escalation is attributed to a much darker and more dangerous Gotham. (as if it wasn't enough of a hellhole before)

Damian takes the advice he’d gotten from his father that “victory is in preparedness” by having booby trapped every single prominent building in Gotham. He may also have literally sold his soul to the devil in return for Gotham's survival although the story is vague on what that actually entails. Needless to say this is not your father's Dark Knight.

Damian has little regard for others opinions of how he follows his fathers legacy. He's hunted by Barbara Gordon (now police commissioner) and is shown to have frequent contention with Conner Kent. (now Superman)

While he does feel some regret for not following his father's iron clad moral code, he protects Gotham in the most effective way he knows, concerning himself more with results rather than being able to sleep at night (or during the day).