Another comic part of the ongoing Dark Nights event is Batman: The Dawnbreaker. In that story, the evil Caped Crusader becomes a coalescence of the Batman and Green Lantern from Earth-32. As with the regular Bruce Wayne, the Bruce on Earth-32 witnesses his parents' murder at
the hands of Joe Chill, but rather than growing up to become the Dark Knight, he becomes the Green Lantern.
At least on that Earth, the Green Power Ring never chooses Hal Jordan or any of the other typical Green Lanterns, but rather presents itself to Bruce, who then uses the ring's raw power to murder Chill and, then, eventually the rest of Gotham's criminal underworld.
When he's finally confronted by the Guardians of the Universe and the rest of the Green Lantern Corps, Bruce uses his newfound ability to wipe them all out.