Violence Jack was an undercover cop who lost his memories because of the earthquake, just like Angel Cop and Mad Bull 34. Some reasons could be:
- It was done by Ichiro Itano.
- He was from The '80s / The '90s.
Ushio Mizuki, Jack's sidekick in Shin Violence Jack, is actually Tare Makimura, Miki's little brother from Devilman.
When he sees Miki chained and with a mask, he grows terrified and runs away. When he finally stops, he realizes that he was about to remember something that was so frightening that he couldn't bring himself to remember it. What his memory is repressing is his horrible death at the end of Devilman, when the lynch mob decapitated him before they killed Miki. Likewise, when he runs back to help her ("even if it makes me remember"), he says to himself that he can't run away because otherwise he would go back to "being the cry-baby I was when I was little," which is an apt description of Tare in Devilman. Violence Jack is Samurai Jack.
Jack is the reincarnation of Akira AND Amon
Follow my logic here. Jack's personality seems like a combination of the two, and in addition, he has traits that wouldn't make sense if he was purely Akira or purely Amon.
Akira evidence
- Satan is actually overjoyed and obbessed with him, which Neo Devilman and other media have established Satan cared about ONLY Akira Fudoh and couldn't give half a crap about Amon.
- He seems to care for Miki instinctively, another Akira thing
- His speech to Mondo during the El Dorado arc mirrors Akira's various "The Reason You Suck" Speech that he would give out to various demons.
- His interactions with children is much nicer and less murderous or simply annoyed as Amon's interactions with them in the OVAs and Amon's manga.
- Looks like an adult, muscled Akira.
- Willingly gives his powers to those who need it twice
Amon evidence
- Has Amon's markings from Demon Knight in Shin Violence Jack,
- Actually gives a crap about Siren
- His speech on Might Makes Right in the Slums arc
- His apparent knowledge on the goings on of The Skull King.
These are massive contradictions.....unless they aren't. My theory is Violence Jack is the reincarnation of all of Akira and Amon's good traits (Akira's humanity, curiousity and morality, Amon's powers, approach to combat, and fighting philosophy.) Skull King is the incarnation of what was left, hence why all they feel is despair and disappointment, even in acts of violence.
- It is also possible that after Akira disappears in the ball of light with Satan at the end of Violence Jack Akira's half disappeared with him, leaving behind only his bad emotions as Shin Violence Jack takes place afterwards. Jack is shown to still exist at the end of Violence Jack. He is now treated as Amon by his fellow demons and not as Devilman, meaning he potentially has inherited enough good qualities to fight for humanity himself just as Akira did. Xenon, who was still around at the end, likely takes advantage of the situation to make Akira's dark side into the Skull King. Himself being Skull Castle and the "Dark Side" of Satan due to them fusing together in ages past.
All of the giants that show up in the series are the reincarnations of demons and devilmen.
Both Violence Jack and the Slum King are inhumanly tall (approximately 9 feet) as are Jim Mazinger and Mad Saurus. In the finale of the first series it was revealed that Jack and the Slum King were the reincarnations of Akira Fudo/Amon and Zenon, respectively, but no such explanation is given to the blind martial artist or the leader of the Mad Riders; but it’s still unlikely that they could be that tall naturally unless they also had demon blood. They might have been involved in the final battle and after the dust settled woke up in the state they are now.