- Jinmen. Check out Tear Jerker for what he's done, but the sheer glee in which he takes from it, the taunting, the way he defends himself from Devilman...it's simply horrifying."Compared to you, I'm like a cherub! ... Humans are my nourishment. For a demon, it is not a crime to eat living beings. After all, humans eat cows and pigs, right? However...killing other living beings is a sin! Isn't it? That's why I ate them without killing them! Without Killing! Without Killing! I Ate Them! Kah Kah Kah Kah! Don't you think they're happy to have been eaten by me?!!!"
- The faces of those he's eaten appear on his shell, still alive, and still conscious until he's done digesting them.
- And then there's his partner in crime in the original manga, the demoness Aleda. She lowers her fur coat to reveal that her whole torso is a face with eyes for breasts and a slasher smile about its abdomen!
- When an angry mob descends on the Makimura's home...and tear both Miki and Tare limb from limb (Tare first, in front of Miki) cements the idea that as evil as the demons are, humans can be just as bad.
- A short interlude where Tare's best friend confides in him that he's being abused at home takes a turn to somehow even darker territory when said friend is torn to pieces by his demonically possessed parents. The last shot of the chapter is of his horrified severed head with pieces ripped out of it sitting in the darkness, with a rather ominous statement just above it.From then on, demons had begun their infiltration into human society...
- In the second volume of the original Manga, Sirene's injuries over the course of her fight with Devilman become more and more debilitating, so much so that the OVA based on the events of Volume 2 are considerably Lighter and Softer despite being gory in their own right. When Devilman rips off Sirene's left wing, he takes off most of the left side of her face with it. The result isn't pretty◊.
- A spider-demon burrowing out of a girl's face. It had taken control of her mind, gradually eating it away until the body had begun to rot.
- Amon eating Yumi, a child Devilman alive in Amon: Apocalypse of Devilman. Note, this is Akira in a Despair Event Horizon/Heroic BSoD after witnessing the brutal aftermath of Miki's murder. And the young Devilman? She was one of his allies.
- Between the amount of Made of Plasticine and the extreme downer ending, it's already pretty dark. It enters new levels when Plucky Girl Miki is torn apart by an angry mob and in some adaptations, her head put on a pike. Her little brother too. The hero arrives far too late, Akira's ensuing Roaring Rampage of Revenge is off panel, but the ground is covered in blood. The last panel Miki appears in has Akira weeping, the last bit of his humanity dead while clutching her severed head. Then it gets worse.
- The humans transforming into demons during the Sabbath, some of them have their skin melting off and others have their bodies ripping apart as they transform, one girl's head is perched on top of her new one and still blinks.
- Just how much the series slides From Bad to Worse over the course of it is genuinely chilling to watch. While Devilman looks like he stands a decent chance against his demonic foes if he takes them on one at a time, the demons soon figure out humanities biggest weakness- fear- and began launching a series of terror-strikes on humanity. With demons declaring an all-out-war, Akira's only hope is to create an army of Devilmen in response to save humanity. Unfortunately, things go off the rails pretty quickly. First, humanity begins fighting against both demons and Devilmen, refusing to trust them, while Ryo seems to have gone completely insane and turns his back on Akira. Second, humans have begun to torture and kill everyone who's associated with demons even slightly, thanks to Ryo publicly stating a bunch of false information on how demonic possession actually works. Third, despite raising a decent following in the Devilmen Corps, Akira soon loses Miki and her family to the insane hordes of humanity, and states that there's no hope left in his heart- only despair, and determination to defeat Satan and save what's left of humanity. The Final Battle ensues, and Akira is killed. Satan is implied to die soon after, with God's angels coming over the horizon to slaughter her as well. Damn.
Nightmare Fuel / Devilman
This series is one of the earliest horror manga out there. As such, it is rife with Nightmare Fuel throughout its run. Here are the ones that take the cake.