Violence Jack

Violence Jack is a horror manga series by Go Nagai. It is known for having several serializations and one-shots that span twenty years (making it Nagai's longest running series) in addition to the intense violence and appearances from his other characters. The series is focused on Earth after going through a catastrophe that lead to Tokyo being disconnected from the rest of Japan and the land being torn apart in a survival of the fittest style. Within the chaos is a large amnesic man known only as Violence Jack. Jack gained his name for the violence that he gets himself and others into and the giant jackknife he wields. The original manga later reveals the world to be a remade version of Earth by God as punishment for Satan for his actions in Devilman. Jack and his extensions of power are later revealed to be the body and will of Devilman who manages to defeat Satan by regaining his original form. Subsequent manga tended to ignore this plot twist and have Jack as his own person. Despite fan opinions, Nagai considers this manga as being separate from other franchises; having the events take place in an alternate reality.

Mazinger Influence
Several characters from the Mazinger franchise appear in Violence Jack including a human version of Mazinger Z named Jim Mazinger and Koji Kabuto as a child. They also have a story arc dedicated to them called Castle of Iron in the form of a karate training genre along with other characters from the series like child versions of Sayaka and Boss, Aphrodite A as a woman with an Afro, Diana as a part African woman with blonde hair, and even Kenzo Kabuto. The main conflict is a turf war between these characters and Count Brocken before they face off against the second generation Kikaido Karate user, Dr. Hell who had assassinated Koji's grandfather Juzo Kabuto.

Aila Mu from God Mazinger appears as a semi-recurring character, appearing as a model who recently became leader of a community of women that were under pressure by two other communities. They get help from Jack to escape from the underground complex they were trapped in.

Tetsuya and Jun were also featured as major characters. Tetsuya was killed by the biker gang Hell's Wind after they topple his car prior to the coming tragedy. Jun (bearing her TV Magazine manga appearance) survives the ordeal and vows to hunt down the biker gang to avenge Tetsuya, coming into contact with Jack.

Violence Jack in Mazinger
The Kurogane House features characters from Gakuen Taikutsu that play a large role in Violence Jack. Tsubasa Nishikiori is among them, who later appears in Shin Mazinger Shogeki! Z Hen as the mother of Koji and Shiro Kabuto and a former collaborator of Dr. Hell.

The Mazinkaiser SKL OVA features a plot similar to the Evil Town arc of Violence Jack, three armies that want dominance over each other (one even being lead by Aila) and the SKL's role taking a parallel to Jack.