Jack's motivation is getting home, and he'll do anything to make it happen. He doesn't enjoy fighting or seek out conflict, but when it finds him, he does what he has to protect himself and the innocents around him. While he's a force of justice, his adversary revels in killing and controlling those who work for him.
Jack is a sword-wielding samurai, but he mostly battles robots and other machines, so what looks like blood is actually gushing oil and other fluids. Some scenes show more human suffering, as when Jack imagines seeing his father burning alive on a cross. Much cartoon violence and weapons like knives and handguns. Stabbings, hand-to-hand combat. Kids are trained to fight for a villain.