I didn't think Ninja Scroll was taht bad... I think the series was worse. And I haven't seen X but I wouldn't have thought it would be as bad as Gantz. Or Ail Manix.
Three episode Ail Maniax: Inma Seifukugari & Majogari no Yoru ni adult anime series from 2001. Once before I've heard the adjective "gore-nography," a sort of English equivalent of the Japanese phrase "ero guro" (itself a modification of the English words "erotic grotesque"😉. That term perfectly describes this depraved and shocking exploration of erotic horror. Besides featuring the theme of sexual molestation and torture, the Ail Maniax series contains several memorable scenes of unbelievable extremes. In several extended sequences in this series, the sexual activity of penetration is exponentially increased by literal vampires and succubi that penetrate the flesh of helpless young women. A policewoman is invaded by a vampire that literally strokes her from the inside by submerging his arms beneath her skin. And a Shinto priestess is literally impaled repeatedly by having multiple large spikes driven into and through her body while she's being raped. Even for someone used to seeing graphic violence and gore in films, the expressions of pain, shock and horror from the victims, and the sheer outrageousness of these graphic depictions of violence make the Ail Maniax series particularly difficult to take.