The first half of the movie is very light on violence or action, apart from a city destruction scene and a car chase. In the second half, there is frequent violence involving gunfire, explosions, superpowers and hand to hand combat yet little to no blood is shown throughout the film.There are several implied deaths, but very few are shown.
The opening scene shows a child's parents being murdered in front of him. Although nothing is really shown, in terms of bullet impact, the scene may be too emotional/distressing for some. The father goes to punch the attacker, but is shot off-screen and then the mother wrestles with the attacker before being shot, again, off-screen. You see the parents' faces as they die.
A scene of mass destruction is shown as several dozen buildings collapse and explode, implying thousands or tens-of-thousands of deaths, but not a single one is shown on-screen. A man is found with his legs crushed beneath a large object, implying they are crushed, but aside from him not being able to feel them and some amount of blood there's not much more, in terms of injury detail, to that scene.
A man is found with a bat-symbol, burnt onto his chest like he's been branded. Photos show a man who's been killed in prison as result of his "bat-branding". The burn mark is shown again, briefly.
In a dream/vision, a group of soldiers shoot another group of men with no blood. Then a vigilante fights the soldiers, punching and shooting them, before snapping a man's neck, which is shown and heard. Later on in the dream/vision, a superhero walks towards the restrained vigilante who is now tied up before he shoots lasers at the two men next to the vigilante, killing them off-screen.Their muffled screams and the splatter of their guts is heard. The superhero shoves his hand into the vigilante.
At a senate hearing, a bomb in a man's wheelchair goes off, implying that everyone in the room, except the superhero, who appears to suffer no injury from the explosion, is killed.