[[caption-width-right:350: It's easy to forget how gruesome this series can be sometimes.]]
Spoilers below.

* Hisoka tied with razor-sharp wire to an upright bed, while being forced to remember the night Muraki raped him.
* Sangatanus feeling-up "Hijiri" ([[spoiler: actually Hisoka in disguise]]), then [[spoiler: brutally murdering him]]. ([[spoiler: because it was Hisoka, a Shinigami, he got better.]]) That entire plotline was massive ParanoiaFuel. Getting an organ transplant? Not usually AFateWorseThanDeath. Having said organ come from someone who made a DealWithTheDevil, and now said devil has declared you fair game? ''Not good at all''.
** [[spoiler:Kazusa]]'s death. We don't see it happen, (though the manga shows us the--thankfully not graphically detailed--results) but we do know that [[spoiler:she [[HeroicSacrifice pushes Hijiri out of the way of a collapsing pillar]], meaning that she was ''crushed to death underneath it'']]. She gets better, but ''still''. Oh, and did we mention that she appears to be [[spoiler:''eight years old'']]?
* The St. Michael's School arc, which was so horribly full of NightmareFuel and {{Squick}} that the author made the next arc as an apology.
** To elaborate, a boy feels so guilt-ridden over [[{{Gayngst}} engaging in gay sex with his teacher]] that he [[spoiler: self-mutilates - cutting off his fingers and burning his genitals, to name a bit of what he does to himself - until he ''dies'', and is thrown into the ocean]]. His classmate finds out about this and threatens to out the teacher, so what does the teacher do? [[spoiler: Sleep with him, and then brutally murder him mid-coitus]]. The first boy's [[spoiler: reanimated corpse, now possessed by a demon, reappears and - bearing in mind that this is a ''corpse'' that has spent a lot of time in the water, and thus is extremely decomposed - seduces the teacher, kissing him even though half his face is falling off. And then he sucks the guy's organs out]]. It's about as disgusting as you can imagine.
* The reason Muraki obsessively stalks Tsuzuki? He wants to put his brother's head on Tsuzuki's body, bring Saki to life, and kill him.
* Muraki in general. Murderer, rapist, driving everyone around him insane, manipulative, MagnificentBastard, a doctor (which, yes, should terrify you) and many who see him (he dresses in white, is pale, has pale eyes and hair) think of him as an angel.
* The possible EldritchAbomination that lives in Tsuzuki's head taking on [[AFormYouAreComfortableWith a face he recognizes]] - his own [[CreepyChild from the past]]. He comes complete with a simultaneous TheReasonYouSuckSpeech and BreakingSpeech hybrid. It's notable to mention that after he speaks to Tsuzuki, Tsuzuki proceeds to ''stab'' Muraki. The dialogue suggests it was the child that goaded (or even forced) Tsuzuki to stab Muraki.
--> In order for a flower to bloom beautifully, something must be sacrificed. Do you understand, Asato? Your life is built on the sacrifice of others.
** This entity is [[spoiler:Enma]], which is still terrifying since this means he's [[spoiler:a god who can [[VoluntaryShapeshifting shapeshift]] and enter Tsuzuki's mind, manipulating him to do his bidding.]]
* Volume 11 of the manga aka the '''infamous''' Kamakura arc, all the way through. There's a ''reason'' it's rated M+. Wait, it's not? ''Well it should.''
** To clarify: [[spoiler:Hisoka's father Nagare made [[DealWithTheDevil a deal with a freaky snake god]] and every night the thing tentacle rapes him. Not everything is shown, but it's pretty goddamn obvious. Cue the BrainBleach.]] It's depicted as graphically as possible without getting an R-18 rating.
*** Actually... It's worse than that. [[spoiler: Nagare didn't make a deal with Yatonokami. His ancestor wasn't strong enough to kill the god, and instead imprisoned it in his own body. To keep it from escaping and murdering everyone in the village, the god has been passed down from father to son for generations, each clan head bearing it - and taking the brunt of the rape. ''This is what would have awaited Hisoka, had he not been killed.'']] Woooooow.
** And let's not forget that [[spoiler: Hisoka's mother was forcibly impregnated by the same demon that constantly rapes Nagare, and Rui's pregnancy with Gods-know-what kind of hellspawn has lasted for at least two years. '''In story.''']]
*** [[spoiler:It's not a demon, it's a (vengeful) ''god''.]] Whether that makes it better or worse is up to you.
*** Since Rui is implied to be pregnant with a vessel for Yatonokami, and both she and Nagare are as much Hisoka's parents as they are the current child's, it's reasonable to assume that [[spoiler:Hisoka actually is ''not'' entirely human and his empathic powers are a side effect of that.]]
* Alongside the above, everything about the Kurosaki clan in general. Literally '''everything'''.
** [[spoiler:Ritualistic sacrifice?]] Check. [[spoiler:Severe child abuse, implied to have plagued more than one generation?]] Check. [[spoiler:Infanticide?]] Check.