This wouldn't be a crossover between Doom (2016) and My Hero Academia if there wasn't anything terrifying enough to void your bowels with.
- As awesome as it is, Shigaraki getting absolutely pummeled by the Slayer counts as this, because not only does the Slayer lay into him without letting him recover, he tears the villain's arm off and beats him senseless with it. The "fight", if you can even call it that, is so brutal that even All Might is visibly sickened, and Class 1-A is collectively traumatized from what they see.
- Nine and his cronies from My Hero Academia: Heroes: Rising are back, and they are no less wicked than before. This time, his Meaningful Name stems from his first Pro Hero kill at nine years old instead of the amount of Quirks he possesses, and he's just as ruthless as he was in the film, if not worse.
- To make things worse, Nine leads the Steel Sabers, an infamous mercenary group who are not only feared by everyone, including Pro Heroes, but also have successfuly killed 246 heroes, all with no Quirk usage whatsoever! It's one thing for supervillains to become The Dreaded, but for regular, non-Quirk using soldiers to gain such a reputation brings a whole new level of horror.
- The Slayer versus the team of Pro Heroes led by Endeavor can be this along with Moment of Awesome. You'd think that since the Pros have more experience and skill in using their Quirks, they'd be able to slow the Slayer down for a little bit, but that is not the case. The ensuing fight is so one-sided that they barely even slow him down, and what's more, the story states that this was him not trying to kill anyone! Makes one dread to think of what may have happened had the Slayer not held back...
- On I-Island, everything that makes the Doom Slayer such a terrifying opponent is made worse when he goes on the warpath against the Steel Sabers. Mook Horror Show doesn't even begin to describe the sheer carnage wreaked upon the mercs as much as they deserve every second of their suffering.
- Curator's Breaking Speech towards David Shield is nothing short of chilling, as befitting of the second in command of All For One. By the time he is done psychologically deconstructing David Shield, the man is left an utter wreck, and his daughter Melissa can't even look at her father for his mistakes.Curator: Oh? Your father didn't tell you? David here was so desperate to alleviate All Might's condition that he was planning to hire Villains to override the security system and retrieve the Quirk Amplification Headset as a way to help All Might. He was perfectly willing to endanger hundreds of innocent lives for his idol. [...] Of course, you previously thought that you hired actors pretending to be Villains when in actuality, it was us and the Steel Sabers thanks to our informant. Sam did most of the work for us, but the headset is only our secondary objective. My master's true objective is to show All Might that even his closest friends can fall into the abyss. First it was Sam and now you, David Shield. You clearly didn't care for anyone that could've been killed and you even got your own daughter in mortal peril, all this for All Might's sake. How does it feel to know that you were willing to sacrifice everything and everyone for him?
- As awesome as Vega's speech towards Nine and his cohorts is, it also serves to hammer home how utterly fucked they are in the most straightforward and mechanical way possible.Vega: If you are listening to this, then the Steel Sabers are about to be destroyed. You Villains who do harm against the innocent are a plague upon society. This will not stand for he is coming for you. You cannot plead with him, you cannot reason with him and you cannot bribe him. He is coming to kill you all.
- The body count is beginning to come in, and all the mook-level opponents are dead as of Chapter 15. Nearly ten thousand professional soldiers with all the tools and equipment of the trade, and they were no match for the Hellwalker. Now think about what would happen to Quirk users.
- Chapter 16, dear lord Chapter 16. To say the Slayer decimates Nine and his crew would be a complete understatement. In short, not only does he dominate them in their battle, he slices open Mummy's throat and neck to the point of near-decapitation, tears Slice's scalp and eyelids off before crushing her head into paste, utterly shredding Chimera with his chaingun, and shoves Nine's Taurus revolver down his throat before blowing his skull off!
- We finally get a glimpse into Miruko's Dark and Troubled Past in chapter 17, and boy is it terrifying. As Tiger Rabbit, she was far more violent and unhinged than her present day self, even giving a malevolent smile at a murderer she had at her mercy one time before executing him! No wonder Hawks is worried about her mental health...
- The aftermath of the Slayer's rampage against the Steel Sabers is revealed in chapter 17. Thousands of Steel Sabers, in various states of dismemberment and/or disembowelment, lay all across the island. And so much blood was spilt that it formed an ankle-deep lake.
- Chapter 18 finally shows us what the Quirk Amplification Headset can do to its wearers when Wolfram gets his hands on it during the chaos on I-Island, and it is not pretty at all. Not only does it amplify a person's quirk far beyond their normal limits, it can also cause Sanity Slippage by tripling the body's endorphin production way past what should be healthy for the human body. It's so bad that even the Slayer can't help but feel revulsion at its effects.Chapter 18: How did David Shield think this was going to help All Might?
- That same chapter also sees Ragdoll mind-scan the Doom Slayer to pinpoint his location on I-Island only for her to unintentionally take a look into the Slayer's Dark and Troubled Past. Go Mad from the Revelation doesn't even begin to describe her reaction to the horrors she saw in his mind.
- The Slayer brutalizing Endeavor in Chapter 20 and many of the other Pro Heroes in Chapter 21 reads like something straight out of The Boys.
- Chapter 22 paints a pretty grim picture of the aftermath of the I-Island rampage: not only is I-Island coated in enough blood and guts to require extensive decontamination efforts, but its destruction will cause a major economic crisis around the world now that it's unable to produce Support Gear to supply Heroes with. Sleep tight!
- Rokuro Nomura, formerly known as the Semtex Hero: C4, makes his debut in Chapter 24, and we have a pretty good idea of the person he is when he casually kills two police officers and a high-school aged girl who showed up at the wrong time just because he felt like it.
- Chapter 26 shows that Ragdoll still hasn't recovered from reading the Slayer's mind, nearly gouging Miruko's eye out with a scalpel when the rabbit heroine is sent to retrieve her and drawing nightmarish pictures of the Slayer and the demons.
