Shelluva Boss is a crossover between Teenage Mutant Ninja Turtles and the Hellaverse, specifically focusing on the 2003 animated Turtles meeting the characters of Helluva Boss, written by Lightyearpig that began in January 2024.
When I.M.P is hired to kill the Teenage Mutant Ninja Turtles, things sure do happen! Namely, their client happens to be the Shredder, who steals Stolas's grimoire to conquer both Hell and Earth, forcing the Immediate Murder Professionals to form an uneasy alliance with the Heroes in a Half Shell to stop Ch'rell, Oroku Saki and Kavaxas from enslaving the living and the dead.
The story can currently be found on Fanfiction.net
and Archive of Our Own.
Shelluva Boss contains examples of:
- Adaptational Species Change: Anton and Owen are strongly implied to be their universe's equivalent to Bebop and Rocksteady. However, instead of being mutated into an anthropomorphic warthog and rhinoceros by the Shredder, they're instead turned into their respective animals when they enter Hell.
- Kavaxas is changed from a Demodragon in the 2012 animated series into a Sinner who Was Once a Man here.
- A Hell of a Time: The Utrom Shredder is practically thriving in Hell since he's already a cruel, violent megalomaniac to begin with, and he makes the most of his time there by rebuilding the Foot Clan.
- Bitch in Sheep's Clothing: Ch'rell lies about being a heroic figure in life who claimed that the Turtles were the real villains. Blitzo buys the act hook line and sinker, but Moxxie has his misgivings about Ch'rell. When Striker arrives after I.M.P leaves for New York, he states how funny he finds it that I.M.P managed to fall for it.
- Black Comedy: As is typical for the Hellaverse, there's plenty of dark humor. One particular example is when the Turtles first discover I.M.P in the first chapter after they murder Hun's group of Purple Dragons. Michelangelo accidentally steps on a heart that he identifies as belonging to Anton since Mikey heard that Anton has valve disease.Michelangelo: Poor guy's never gonna get treatment now.
- Breather Episode: Compared to the violence and action of the first chapter, the second chapter is meant to be set-up for the remainder of the story, showcasing the Turtles and I.M.P getting to know one another, introducing characters like April, Casey, Master Khan, and the Overlords, and showing more of the Shredder gaining power in Hell.
- Call-Back: Many to both shows.
- Ch'rell first meets Blitzo while the latter is imagining himself in a threesome with Moxxie and Millie like in "Loo Loo Land".
- When Ch'rell hires I.M.P to kill the Turtles for him, he describes his enemies with much of the same dialogue he used when describing the Utroms to Leonardo in "The Shredder Strikes". Fittingly, he also introduces himself as Oroku Saki to Blitzo.
Ch'rell: You see, before I was wrongfully banished here, I was a humble man who had seen enough of the world and beyond to expect the extraordinary. And trust me when I say that Hell has truly been extraordinary so far, but as I said, I did not deserve to come here. I was condemned to spend the rest of eternity in this cesspool of villainy by a malevolent force of ninja that I have worked tirelessly to defend the world from. This is a corrupt and evil force that is out there right now in the living world, working its insidious tentacles into every aspect of humanity. They are an organization devoted to obtaining power through crime and corruption on a global level. Unfortunately for them, I was the only one who dared stand against them as my master and his master did before me. Although it was my destiny to save the human race and lead them into a new era, I was robbed of my victory in the end. If you and your associates can find it in your hearts to stand with me, you will be given everything you could ever want.- Blitzo intially objects to Ch'rell suggesting that Loona come with the imps to kill the Turtles because Ch'rell has "no idea what kinda hormonal freaks would drool all over her!" He, Loona, Moxxie, and Millie glare at the audience while Ch'rell has no idea what they're staring at.
- When urged by Moxxie to keep a low profile so they can preserve The Masquerade, Blitzo objects by claiming how Humans Are Morons and that D.H.O.R.K.S has yet to come back for revenge. Meanwhile, Loona adopts her human disguise while agreeing with Moxxie.
- When Loona watches Irma reporting on the Purple Dragons' crime spree, she compares it to the "City at War" storyline where the Purple Dragons went to war with the New York mafia and the Foot remnants in Season 2.
- Millie comments on how New York looks way better than Los Angeles, which they visited in "Seeing Stars".
- Raphael mentions how Hun was turned into a mutant turtle in Turtles Forever, and wonders if he's stuck like that. Hun later reveals that he strong-armed Baxter Stockman into making a retro-mutagen for him.
- When asked by Moxxie if the Purple Dragons knew the Turtles, Hun reveals how the Turtles have been up against criminals, alien warlords, supervillains, and monsters from other dimensions.
- Hun asks where I.M.P gets their weapons, to which Blitzo replies with "Yo mama."
- When Blitzo fires his gun at Leonardo, his bullet hits Leo in the spot where Shredder broke off a part of his shell in “Exodus" that has since healed over.
- During Raphael and Loona's fight, Raph taunts Loona by asking if she's had her shots yet, to which Loona replies that she did in “Western Energy".
- In the first episode of Back to the Sewer, the Turtles encounter a possible future where the Utrom, Demon, and Cyber Shredders are at war with each other. This would eventually come to pass in the present, only this time the three Shredders have teamed up.
- The Cyber Shredder is shown to be inhabiting the body of Robo-Fizz, who was previously destroyed in its singular appearance.
- Ch'rell's Cold Opening narration begins with the final battle against him at the end of Turtles Forever, where he attempted the complete and utter destruction of the Ninja Turtles multiverse by destroying the prime universe Turtles from the Mirage Comics before being destroyed by his own upgraded Technodrome.
- Blitzo introduces I.M.P to the Turtles by singing their theme song from the pilot episode.
- When Michelangelo mentions the Garbageman as a possible suspect as to who hired Blitzo, he also references the events of the unfinished fifth season episode "Nightmares Recycled", which ended with the Garbageman falling into a vat of acid. The Garbageman himself later references how he was originally going to be Hun's conjoined twin.
- Raphael and Donatello bring up Savanti Romero and Drako as additional suspects, who were Killed Off for Real at the end of the fourth season two-parter "Return of Savanti" and the third season's Ultimate Drako arc respectively.
- Upon realizing that I.M.P was hired by the Shredder, the Turtles describe Ch'rell in a similar fashion to how they talked to the 1987 Turtles about him Turtles Forever.
Leonardo: He's vicious.Donatello: Lethal.Michelangelo: Competent!- Splinter's retelling of the Turtles' origins recaps what was previously seen in "The Shredder Strikes" and “A Better Mousetrap”, while also alluding to the deaths of Tang Shen and Yukio Mashimi in "A Tale of Master Yoshi".
- The Turtles' current reservoir station lair has sustained serious damage since being attacked by the 1987 Bebop and Rocksteady, and they're considering moving to another lair.
- Ch'rell and his allies intimidate the Overlords into serving the Neo-Foot Clan by presenting them with the corpses of two Overlords resembling Ars Goetia demons that were glimpsed in the Hazbin Hotel pilot.
- After her fight with Raphael, Loona references how she was living in a dog pound before being adopted by Blitzo.
- Sir Pentious mentions having been taken in by the Shredders after being defeated by Alastor in the Hazbin Hotel pilot, followed by Drako, Savanti Romero, and the Garbageman revealing how they were recruited after their deaths.
- Cletus, Collin, and Keenie are shown as members of the Neo-Foot Clan, having been presumably been recruited after being exiled from Heaven.
- Serling from the sixth and seventh seasons is revealed to have been returned to 2105 at some point, which explains his What Happened to the Mouse? status in Turtles Forever.
- April briefly confuses I.M.P for the Horsemen of the Apocalypse, saying that this isn't the first time she helped stop The End of the World as We Know It.
- While explaining what he researched about Hell to April and Casey, Donatello brings up how Lucifer Morningstar is a separate entity from Satan.
- Master Khan is mentioned to be in prison for his failed crash of April and Casey's wedding in the Grand Finale "Wedding Bells and Bytes".
- Millie brings up I.M.P's previous encounters with Striker after his attack on Rikers Island makes the news.
- With Stolas's grimoire in the Shredder's clutches, Donatello decides that they should use an Asmodean Crystal in order to enter Hell. Coincidentally, this leads to a news report about the Earth Protection Force capturing Barbie Wire, who is revealed to be in possession of one in “Unhappy Campers".
- After Channel 6 reports on Barbie Wire's capture, Blitzo declares "Well, Christ on a stick, I guess there is a god."
- Michelangelo mentions how Agent Bishop would eventually have a future Heel Realization and become president of Earth in 2105.
- Canon Immigrant: Kavaxas, a character created for the 2012 animated Turtles series, is featured here as one of the Overlords of Hell and an ally of Shredder.
- Content Warnings: Similar to the content warning at the beginning of most Helluva Boss episodes, this crossover features one that sets the mood nicely.WARNING: THE FOLLOWING CROSSOVER CONTAINS LANGUAGE AND VIOLENCE NOT SUITABLE FOR MINORS. IF YOU ARE UNDER LEGAL DRINKING AGE IN WHEREVER YOU LIVE IN, PLEASE KINDLY GO FUCK YOURSELF BECAUSE THIS STORY CLEARLY ISN'T FOR YOU. IF YOU INSIST ON STICKING AROUND, DON'T SAY I DIDN'T WARN YOU, BUT I WON'T TELL IF YOU WON'T.
- Coincidental Broadcast: Twice in the first two chapters. The first one has Loona looking at her phone only to watch a news report about the Purple Dragons, which is what leads them to the Ninja Turtles. The second happens when Donatello says they need to find an Asmodean Crystal, which prompts some breaking news about the Earth Protection Force capturing Barbie Wire and keeping her crystal for research. Millie lampshades the first one.Millie: I'm more concerned about how Loona pulled out her phone at just the right moment.
- Continuation Fic: Shelluva Boss follows up on Turtles Forever with the Utrom Shredder now residing in Hell after his seeming final defeat and plotting revenge.
- Conspicuous Trenchcoat: Blitzo, Moxxie, and Millie don these disguises in New York after Blitzo found them in a store. The disguise falls apart pretty quickly once Blitzo kills a man in public.
-
Crossover Ship: Loona and Raphael get some Ship Tease together in their scene in Chapter 2. - Cuteness Proximity: Millie absolutely adores Michelangelo's cat Klunk upon first meeting him.
- Darker and Edgier: This is far more violent and foul-mouthed than the author's usual stories, a fact that he's proud of for writing his first M-rated story.
- Demographic-Dissonant Crossover: The usually family-friendly Ninja Turtles cross paths with the cast of the adult cartoons set in the Hellaverse. While the Turtles have targeted older audiences and tackled darker subject matter before, with the 2003 animated series being acclaimed for sticking the closest to the original Mirage Comics compared to other versions of the franchise, Helluva Boss on the other hand is a violent and raunchy adult comedy taking place in Hell. The author is aware of how bizarre this idea is, but he also states that he managed to make crossing Gravity Falls over with both FLCL and Soul Eater work when he wrote Fooly Falls and Gravity Soul.
- The Dragon: Striker is this to Ch'rell and the Neo-Foot Clan.
- The Dreaded: The Utrom Shredder is this as expected, with the mere thought that he's still out there and plotting his revenge causing the Turtles to panic and Leonardo to pin Blitzo against the wall. But according to
Word of God on his DeviantArt account, Alastor is the only resident of Hell that Ch'rell is terrified of, as his presence serves as a reminder that Ch'rell will eventually become another one of Alastor's victims. - Evil Power Vacuum: Ever since Turtles Forever, the Purple Dragons have been attempting to fill the void left by Shredder after his disappearance.
- Foil: The Turtles and I.M.P turn out to have more in common than they realize.
- Leonardo and Blitzo are The Leader of their respective groups, only Blitzo has far more issues than Leo.
- Donatello and Moxxie are the brains of the teams, but Moxxie lacks Donatello's self-confidence.
- Raphael and Loona both fill the role of The Big Guy, but Loona has trouble with being treated as a mature adult by Blitzo while Raph carries the burden of keeping his brothers out of danger.
- Michelangelo and Millie are the Fun Personified who both have issues with being seen beyond their basic personality traits, with Millie wanting to be seen as more than Moxxie's Cute and Psycho wife while Mikey claims to be deeper than just being the funny wise guy.
- To a lesser extent, the Earth Protection Force serves as this to D.H.O.R.K.S by being way more competent.
- For Science!: Donatello and Moxxie's scene in chapter 2 has Donnie running experiments on Moxxie for the sake of researching Hell, including checking if he really has a Teeny Weenie like Loona keeps mocking Moxxie for. According to a very uncomfortable Donatello, Moxxie's dick is only slightly below the average size of a human penis.
- Fusion Fic: The worlds of both Teenage Mutant Ninja Turtles and the Hellaverse are merged into one like many of the author's other stories. Due to the 2003 series being a children's show that mostly abided by television censorship laws of the 2000s, Heaven and Hell are never really elaborated upon as concepts, allowing the opportunity to confirm that in this universe, Vivziepop's version of Hell is the Hell of this universe.
- The Gadfly: While meditating with Leonardo, Blitzo makes fart noises with his mouth and accuses Leo of farting, much to the turtle's annoyance.
- The Ghost: Thus far, Stolas has been alluded to multiple times but has yet to make a physical appearance.
- How the Mighty Have Fallen: Subverted with the Shredders. Despite being damned to Hell for their crimes, the three were able to make the most out of it by being their usual monstrous selves and gaining massive amounts of power in the process.
- How We Got Here: The story begins with the Ninja Turtles battling I.M.P in a warehouse on New York Harbor that is decorated with the bloodied remains of numerous Purple Dragon thugs. Up until the climax, the first chapter is devoted to how it got to that point.
- Indy Ploy: After coming to the conclusion that I.M.P likes using this tactic, Leonardo comes up with his own plan on the fly to knock them all out.
- Internal Reveal: I.M.P learns of the Turtles and Splinter's origins in chapter 2, where the Turtles likewise learn that Shredder wants them assassinated.
- I'm Standing Right Here: Ch'rell invokes this when Moxxie voices his reservations about the Shredder as a client.Ch'rell: You know, Mr. Moxxie, it's rude to talk about someone when they're right in front of you. You should discipline your employees more, Blitzo.Blitzo: Trust me, Saki. The whole universe is out to discipline him for whatever reason every waking moment of his life.
- Knight of Cerebus: As usual, the Utrom Shredder darkens the mood in every scene he's in, particularly when he presents the dead bodies of a pair of Overlords he killed before forcing Carmilla Carmine to serve him by threatening his daughters' lives, and later ordering Striker to murder everyone in Rikers Island.
- Leave No Witnesses: Ch'rell orders Striker to murder every last prisoner and guard at Rikers Island after stopping by to collect Master Khan and recruit him into the Neo-Foot Clan. Hun is the only other survivor of the massacre due to following Shredder back to Hell.
- Legion of Doom: The Neo-Foot Clan, led by the Utrom, Demon & Cyber Shredders and Kavaxas, consists of many prior antagonists of both I.M.P and the Ninja Turtles. Of note are the generals, consisting of Striker, Fizzarolli, Verosika Mayday, Sir Pentious, Crimson, Master Khan, the Garbageman, Drako, and Savanti Romero. Other members include Vortex, the Foot Mystics, C.H.E.R.U.B, the Necro Monster, and later the Vees and Hun.
- The Legions of Hell: The Utrom Shredder's new Foot Clan consists of many residents of Hell, ranging from hellborn demons to sinners like him, the other Shredders, Kavaxas and the Vees, the Garbageman, Savanti Romero, and Drako.
- Let's You and Him Fight: Ch'rell pits the Immediate Murder Professionals against the Teenage Mutant Ninja Turtles as a way of keeping them both distracted while he uses Stolas's grimoire for his own evil plans.
- Like a Son to Me: Inverted. Michelangelo jokingly calls Millie mom when she tells him not to spill his tea, which causes Millie to burst into Tears of Joy over being called a mother.
- Mama Bear: Carmilla Carmine is forced to submit to Ch'rell when he threatens her daughter Odette's life.
- Manipulative Bastard: Ch'rell manages to successfully convince I.M.P to hunt down the Turtles and hand him the grimoire for protection.
- Mass "Oh, Crap!": Blitzo and company start running for their lives when Blitzo is caught shooting another man in public.
- After Leonardo knocks Blitzo out with a blow-dart, he throws an explosive shuriken to take down the rest of I.M.P. Millie and Loona frantically order Moxxie, who caught the shuriken, to throw it away before it explodes in their faces.
- The Turtles have this reaction when they learn that I.M.P was hired by Ch'rell.
- The Overlords of Hell have this reaction to Shredder carrying Stolas's grimoire and killing two of their own to intimidate them into joining him, the only exceptions being the Vees and Zestial.
- Mauve Shirt: Subverted with Anton and Owen, a pair of Purple Dragon Mooks who are murdered by Blitzo after the two get a decent amount of screentime, only for the two to appear in Hell as the story's equivalents to Bebop and Rocksteady before getting recruited by the Shredder.
- Mythology Gag: Many to the wider Turtles franchise, as this is meant to be a celebration of its fortieth anniversary.
- Blitzo's narration during the Cold Opening evokes similar narrations from the 2003 series's cold opens in the first five seasons in addition to the frontispieces from the Mirage comics, complete with Blitzo saying "Let me tell you a story." Prior to that, Blitzo declares "Tonight, I dine on turtle soup!"
- Blitzo, Moxxie and Millie disguise themselves with trenchcoats and fedoras like the Turtles would sometimes use when going up to the surface, mainly in the 1987 cartoon. Millie then says "Here's looking at you, kid!" in a Humphrey Bogart voice much like Raphael did when the Turtles were adopting that disguise for the first time.
- During the elevator ride down the Waldorf Astoria, I.M.P runs into a lawyer named Murphy Lawson, named after Steve Murphy and Jim Lawson, who works for Eastman and Laird, Attorneys at Law. When Blitzo reveals that he's an assassin, Lawson then asks him to kill a Starbucks barista named Venus for getting his order wrong before he's interrupted by the elevator stopping at his floor.
- When Loona gets bored and looks at her phone, she comes across a Channel 6 news report of a Purple Dragons crime spree being reported on by Irma Langenstein.
- After exiting the Waldorf Astoria, I.M.P comes across a man offering them to play three-card monte, echoing a similar situation faced by Leonardo in the first episode of the 80s show. Unlike Leo, who cut the box in half with his sword, Blitzo shoots the man to death, which blows the team's cover.
- Two Purple Dragon goons named Anton and Owen bear a striking resemblance to Bebop and Rocksteady's human forms. Upon entering Hell after becoming victims of Blitzo, their sinner forms are that of a warthog and a rhinoceros respectively.
- Kavaxas is stated to be rather hotheaded, a reference to Hothead from Teenage Mutant Ninja Turtles: Tournament Fighters, who inspired Kavaxas's creation.
- Half of the second chapter's title is "Shredder in Hell", after the IDW miniseries of the same name.
- After the second chapter's Cold Opening, we get this reference to Teenage Mutant Ninja Turtles: The Last Ronin after the Turtles bring I.M.P to their lair.
Raphael: If you guys don't wake them up soon, I'm eating the last bagel.Michelangelo: Hey, sleeping beauties, wake up. We got things to do.- After Splinter concludes his flashback, Blitzo says that he thought Splinter Was Once a Man, which Donatello says is the origin story of the 80s' cartoon Splinter.
- The Turtles have been thinking of moving to another lair, with Donnie mentioning an abandoned church in Alphabet City where they took up residence in the IDW comics.
- Vernon Fenwick reports on the Purple Dragon massacre from the first chapter and interviews Hun.
- Loona and Raphael get some Ship Tease with each other, presumably as a reference to Ninjara and Alopex, who were girlfriends of Raphael that also resembled canines.
- April O'Neil is shown wearing her outfit from the first five seasons of the show beneath a yellow hoodie with the number 5 on it, evoking her counterpart from the 2012 show.
- April and Casey Jones spent their honeymoon in Costa Rica, where Leonardo spent time in TMNT as the Ghost of the Jungle.
- Blitzo mentions the Four Horsemen of the Apocalypse, a possible reference to the horsemen being featured in Teenage Mutant Ninja Turtles Adventures.
- Once Blitzo mentions pizza, Michelangelo yells "LET'S GO FOR IT!" while Donatello says that Blitzo said the magic word.
- Speaking of the 1990s movie, Donatello asks Michelangelo a profound question about whether they'll go to Heaven or Hell. Much like how he was asked about what life could be like for them without Splinter, Mikey acts like he was either not paying attention or deliberately ignoring such a thought.
- Donnie orders some pizza from Antonio's Pizza-Rama, and one of the pizzas he buys includes double anchovies and black olives, which was Splinter's favorite pizza in Teenage Mutant Ninja Turtles Adventures.
- Donatello, Michelangelo, Loona, and Moxxie pick up their pizza delivery at a rabbit-themed Japanese restaurant named Sakai's Japanese Dining, which is right next to the corner on Dooney and Lavigne, named after Michael Dooney and Steve Lavigne.
- Carlos Chiang O'Brien Gambe reports on Striker's massacre of Rikers Island and the Earth Protection Force arresting Barbie Wire.
- Noodle Incident: Raphael once stubbed his toe and swore so much, it practically became a Running Gag.
- Blitzo mentions that I.M.P got into legal trouble with the Horsemen of the Apocalypse after trying to rebrand the company with their name.
- The events of "Nightmares Recycled" are stated to have still taken place, albeit offscreen. Leonardo says he doesn't remember what happened, to which Raphael says he probably wasn't there at the time.
- No-Respect Guy: Due to being Incompetence, Inc., D.H.O.R.K.S is not taken seriously at all by Agent Bishop. However, after their capture of Barbie Wire, Bishop decides to Throw the Dog a Bone for once.
- Nice Job Breaking It, Hero: The Turtles are not happy to learn that Shredder is still out there, and even more when I.M.P realizes they gave him the grimoire.Leonardo: If Shredder has that grimoire, then he'll no doubt use it to return to New York for revenge. Well, congratulations, Blitzo, your greed has officially put Hell and Earth in danger because of a job. Was it worth it?Blitzo: For the kind of money the squid stain was offering? Yeah, pretty much.Raphael: You are truly Mother Teresa, ain't ya?
- Obviously Evil: Ch'rell, obviously, which makes Moxxie the only member of I.M.P to be suspicious of their new client. Even the mere sight of the Shredder sends shivers down Moxxie's spine upon first meeting him.Moxxie: I'm not the only one who feels just a little suspicious about Mr. Saki here, right? I mean, just look at the guy! His armor's covered in blades, he's got that creepy voice, and he has that weird purple scar on his face! Look at him and tell me he wouldn't seem out of place as a supervillain in a comic book, right?
- Oh, Crap!: Hun when I.M.P start murdering his group of Purple Dragons.
- After Blitzo discovers that his team has been compromised and taken to the Turtles' lair, he starts panicking and tries to reach for the grimoire only to realize that he already gave it to Shredder.
- Hun has this reaction when chasing Shredder and Khan into Hell and meeting the Neo-Foot Clan.
- Orcus on His Throne: Invoked by Ch'rell as a means to overpower the Turtles once they eventually come after the Neo-Foot Clan in Hell. Aside from returning to Earth to break Khan out of prison, he's making good on that promise.
- Papa Wolf: Upon learning that I.M.P was hired to kill the Turtles, Splinter tells Blitzo that he's keeping an eye on him.
- Pizza Boy Special Delivery: Parodied when Loona uses her human disguise to pick up the pizzas Donatello ordered, causing the pizza boy to fall head over heels for her. When the pizza boy asks if Loona is doing anything later, Loona instead blows him off.
- Prank Call: When Donatello orders some pizza from Antonio's Pizza-Rama, Blitzo interrupts the call to say that the order should be delivered to someone named Isee Youpee.
- Precision F-Strike: Hun, who usually says "Aw crud" in lieu of any actual swearing, does this after accidentally wandering into Hell while chasing Shredder and discovering the Neo-Foot Clan.Hun: Shredder, what the fuck is going on here?!
- Psycho Rangers: The Neo-Foot generals are set up as Evil Counterparts to I.M.P and the Turtles.
- Striker to Leonardo.
- Sir Pentious to Donatello.
- Verosika Mayday to Raphael.
- Fizzarolli to Michelangelo.
- Master Khan to Blitzo.
- Savanti Romero to Moxxie.
- The Garbageman to Millie.
- Drako to Loona.
- Red Oni, Blue Oni: Fittingly, Blitzo and Leonardo, which is best exemplified during their battle in the first chapter. In contrast to Leonardo and the other Turtles being trained since childhood in the art of ninjitsu, Blitzo and I.M.P are Weak, but Skilled and prefer to wing it in fights.
- Religion of Evil: Kavaxas is said to have been a cult leader in life before becoming an Overlord through building another cult.
- The Rival: Verosika and Velvette are implied to be this given their frosty greeting towards each other when Shredder brings the Vees to the Neo-Foot's headquarters.
- Running Gag: A character getting shocked by I.M.P's swearing followed by saying they haven't heard language that foul since Raphael stubbed his toe that one time, usually leading Raph getting annoyed with it.
- Save Both Worlds: I.M.P and the Turtles have to team up in order to stop the Neo-Foot Clan from conquering Earth, Hell, and Heaven.
- Ship Tease: Loona and Raphael's rematch ends with the two in a compromising position, which Raph finds hilarious while Loona asks if he wanted to have sex as the two Crush Blush at each other before engaging in some awkward silence. It was intended to be a joke, but after readers compared the two's relationship to Raphael's flings with Ninjara and Alopex, the author made the realization that they actually would make a cute couple.
- Shout-Out: Given the author's previous works, this is to be expected.
- When the Shredder first arrives at I.M.P's headquarters, Loona is in the middle of a conversation the existence of good-minton with Vortex. Later, when Moxxie and Millie arrive, Millie says "So anyways, Reg had the ball at the top of the key."
- When Loona first introduces Ch'rell to Blitzo while the latter is pleasuring himself and imagining a three-way with Moxxie and Millie.
Loona: Dammit, Blitzo, I'm saying we just got a client!Blitzo: Did either of you see anything!?Blitzo: GOOD!- Blitzo asks Shredder if he's ordering I.M.P to kill whoever made fun of his Darth Vader cosplay.
- As I.M.P prepares to leave for New York, Blitzo says to hold all songs about how it's a helluva town till after they're done.
- When I.M.P first arrives in New York on the roof of the Waldorf Astoria.
Blitzo: GOOD EVENING, NEW YORK!Man: Hey, fuck you!Blitzo: YES, YES! FUCK YOU TOO!- When Blitzo presents Moxxie and Millie with trenchcoats to use as disguises in New York, Moxxie asks where he got them to which Blitzo replies that it's a very long story.
(cut to a flashback of Blitzo discovering the trenchcoats in a shop window)Blitzo: Neat!- Blitzo calls the Purple Dragons Purple Rain Men.
- While I.M.P is on the elevator at the Waldorf Astoria.
Loona: Where are we?Blitzo: I think we're in the twenties, somewhere.- When Murphy Lawson asks about Blitzo's tail, Blitzo responds by saying "Don't act like you're not impressed!"
- When Blitzo kills the con-man right in front of a bystander, he tries using a Jedi mind trick to convince him not to call the police, but it doesn't work.
Blitzo: Look sir, I think if we all take a couple of deep breaths here and just try to- (runs away before he can finish) FUCK!- When first discovered by the Purple Dragons Anton and Owen, Blitzo accidentally reveals that he's from Hell before correcting himself by speaking Judoon.
- Hun mockingly calls Blitzo Hellboy.
- Millie shows off a party trick to the Purple Dragons where she makes her knife disappear by planting it on a table and slamming a Purple Dragon's eye into it.
- Blitzo calls the Turtles Battletoads when meeting them in person for the first time.
- When the Utrom Shredder stands before his forces at the end of the first chapter.
Neo-Foot Clan: For the Shredder!Ch'rell: For victory!Neo-Foot Clan: For victory!- After Leonardo introduces himself, Moxxie wonders if he was named after Leonardo da Vinci or DiCaprio.
- While catching Leonardo meditating, Blitzo calls him Papa Smurf.
- Moxxie tells Donatello that evil people like Adolf Hitler were residing in Hell at some point, but then one day, they got him.
- Michelangelo and Millie play an indie 3D platformer called Digital Circus Saga. Mike also mentions other video games called Killer Bots and Whackadoodle.
- Millie says "You son of a bitch, I'm in!" after Mikey offers to let her have a turn on his game.
- When Michelangelo turns off his game and changes the channel to Splinter's soap operas, there's an episode of Caleb Rentpayer already in progress.
Tuxworth: Caleb Rentpayer, did you kill Caleb Rentpayer?Caleb Rentpayer: I sure did!- As Splinter enters the room with some tea soon after, he says this.
Splinter: Bryce and Brandon are totally going to get together this season, and I refuse to take anyone who says that Bryce's wife is the real victim of their abusive relationship seriously.- Donatello channels a bit of Charlie Kelly when explaining all he has learned about Hell. Michelangelo wonders if he'll ever start ranting about Pepe Silvia.
- Michelangelo calls Loona Looney Tunes.
- A pizza delivery boy named Philip delivers the pizzas to someone named Isee Youpee, much to his disgust.
- The Shredder orders Striker to kill everyone in Rikers Island after he arrives to recruit Master Khan, similar to the scene in Guardians of the Galaxy where Ronan the Accuser orders his forces to kill everybody in the Kyln.
- Blitzo compares Agent Bishop to Tommy Lee Jones, alluding to his role as Agent K in Men in Black.
- Sir Swears-a-Lot: Blitzo, naturally, which Michelangelo lampshades.Michelangelo: We should really put up a Swear Jar at some point. Seriously, is Hell just full of people who love saying bad words all the time?
- Straight Man and Wise Guy: Leonardo and Blitzo respectively, which the author compares to Steve Martin and John Candy as Neal Page and Del Griffith in Planes, Trains and Automobiles.
- Too Dumb to Live: Blitzo makes many careless decisions that blows I.M.P's cover when they first arrive in New York, like killing a con-man in public and revealing to the Purple Dragons that they come from Hell. He blames this on waking up on the wrong side of the couch when Millie points this out.
- Trapped in Villainy: According to Verosika Mayday, she and most of the Shredders' other minions were forced to serve Ch'rell through being threatened into joining the Neo-Foot Clan, with the exception of Master Khan, the Vees, Kavaxas, and presumably Savanti, Drako, the Garbageman, Striker, and Crimson.
- Uncomfortable Elevator Moment: During I.M.P's elevator ride down the Waldorf Astoria, they have a brief encounter with a lawyer in the building who asks them to kill a barista who got his coffee order wrong that morning.
- Unexplained Recovery: It's currently unknown how the Cyber Shredder is in Hell despite him being a digital engram, thus not an organic being, and how he decided to inhabit Robo-Fizz's body.
- Villain Opening Scene: Shredder narrates the cold opening of the second chapter.
- Villain Team-Up: It's not just the Utrom Shredder plotting his revenge on the Turtles in Hell, but he has also joined forces with the Demon and Cyber Shredders from the fifth and seventh seasons of the show, along with numerous other characters from both franchises to form a Legion of Doom.
- The second chapter adds Vox, Valentino, and Velvette from Hazbin Hotel to the alliance as three of the only Overlords to willingly side with Shredder, and later Master Khan and Hun.
- Weird Crossover: While the Ninja Turtles have gone into darker territory before, they're mostly known as a family-friendly franchise. Helluva Boss on the other hand is an adult cartoon that wears its target demographic on its sleeve.
- We Wait: Shredder elects to wait until the Turtles realize he's in Hell while building his army. That way, the Turtles will be completely overpowered once they try to stop him.
