I once asked a friend of mine, the only other person I know in real life who has read Violence Jack, if she thinks Go Nagai is a smart man. "Of course not" she replied, while still agreeing that Devilman, and many arcs of this manga, are some of greatest works in the entire medium.
Before I read Violence Jack I read that it is one of the most outrageous and graphic things to exist in comics, but nothing was able to prepare me for just how insane this manga truly gets. I can recommend this to people who are very familiar with the entire body of work by Go Nagai, or are masochists, or massive fans of sex and violence, also fans of sagas that last thousands of pages. And if you happen to be all of the above its likely you don't need me to introduce this comic to you.
This is a story set in Kanto. Continuous apocalyptic earthquakes separate the entire region from the mainland creating an island of pure chaos and depravity. The point of view character switches basically every chapter, and so the story is quite episodic. While I could go on and on about the plot I'll spare you those details. What is relevant is that a good portion of things in this manga are reimagines of other Go Nagai comics. Basically every comic he made of any relevance gets a smaller or larger spotlight. While being familiar with all of them helps to make the story more coherent, I would say the only essential comics you need to be aware of are Devilman and Cutey Honey, which you are likely already familiar with. This story is basically Go Nagai playing dolls to create a saga similar to military-historical fiction set in the warring states period.
Somehow, he pulls it off. The world building in this manga is complex and detailed, but flexible enough to allow him to tell any type of story. Some of my favorites are centered around Mando and Mido, a pair of radical extremists who just love violence and decide to travel to the hell-quake infested Kanto. Mido is an inexplicably feminine man who adores Mando, who is a hotheaded man always looking for adrenaline. I would recommend reading this story just for them.
Mido does help to illustrate another part of the manga. He is one of many cross-dressing or openly trans characters. Not all of them are written amazingly, but that goes for all Go Nagai characters. What is important is that Go Nagai has lots of fetishes and it quickly becomes apparent this is one of them. The sheer omnipresence of fetish in Violence Jack makes me question what even is a kink for Nagai and what's a serious attempt at writing. This is a running theme in his manga. As a queer person myself, one who finds great interest in alternative forms of sexuality and its depiction in art, Nagai is something I can never quite crack. Take Iyahaya Nantomo as an example. This simple story of an impoverished boy mistaken for a cousin of a rich family quickly devolves into several volumes of non-stop debauchery. A whole organised tournament takes place seemingly just for Nagai to see how much he can get away with. Considering the similarity in content to Pink Flamingos and Salo: 120 Days of Sodom, the answer is that there is likely nothing he couldn't put onto a published comic. But at the same time its done with so much love. Elaborate bondage patterns, endlessly creative settings, exploration of gender and sexuality that almost feels like its being sneaked into the comic underneath the guise of pointless crudeness. Maybe the idea of pushing boundaries is appealing by itself to Go Nagai, this feels true for his works such as Shameless School. Which by intentionally attempted to stir up controversy among the PTA groups already advocating for the comic to face cancellation. It also less intentionally caused the creation of ecchi as a concept in manga. Although his boundary pushing inclinations are certainly not limited to sex, as there is a reason why this comic has violence in its name.
Its not an exaggeration to say that the death count is either close to equal or far exceeds the page count, not even considering off page deaths. There are avant-garde collages of complete depravity of constant deaths. There's pages that decide to erase any facade of a line between sex and violence and have warfare be superimposed over the top of a sex scene. A rail-gun superimposed over a penis in a sex scene would be blatant imagery about the nature of war and sex in mass media, but does Nagai realise this? There's no way he doesn't, but at the same time it always feels impossible to tell where exactly the line between sanity and madness lies for him.
I think the most important quality of this comic is how it represents artistic freedom. It does it unlike anything else. This is a devastated landscape where Go Nagai creations are free to roam and do their little Go Nagai shenanigans. This is 30 volumes of a guy writing anything he wants at any given second. Bizarre tangents are not uncommon. In one chapter he begins gushing over a real martial arts discipline for too many pages, forgoing any illustrations and just using actual photos. Nagai has not stopped writing even to this decade, and I see this comic as the ultimate personal statement. Every societal injustice is commented on, every possible body part and their combinations are cut off in one swing, every possible “fuck you” is said to the reader, every favorite Go Nagai character is shown going through hell, every fetish in existence gets represented. This comic is equally as great for people who love being scandalised, as it is for people who feel as if they have been desensitised to everything. This is an inkblot test, you can and will likely see and think just about everything one could about a manga.