The series is based around a last stand for humanity against a psychopath scientist and his mutant army. Throughout the series the protagonists are fighting against robots, subs, and ships all of which are mutant creatures. When subs, which are giant whales, are destroyed there is large spurts of blood.
In one scene, a whale who helped the protagonist is torpedoed and slowly bleeds out. The water is stained red around the whale and the protagonist jumps into this water and swims to reach safety. Another scene shows a hand from one of the merfolk hitting the cockpit of a ship.
Violence toward humans is continuous with many explosions and destruction. Submarines and boats are seen exploding and breached sub show the crew areas flooding with people inside. A human facility is shown to be completely destroyed and any individual inside is inferred to be dead.
A final fight scene between a wounded shark creature and the protagonists shows a last violent showdown and is considerably bloodier than the rest of the series. The protagonist is hit hard and punched causing his face to bleed. The shark creature bleeds throughout from wounds in his arm and face.
The edited version significantly tones down the violence; some more violent scenes are cut altogether, while in other scenes the blood has either been digitally removed or recolored.