A long time ago, Izuku Midoriya felt he would have been better off had he been born Quirkless. Instead, he's born with a power that others fear him for. In spite of this, he still strives to become a hero. Now the protege of the No. 1 hero, All Might, he may have his chance to achieve his dream after all. However, the secrets of one's bloodline don't stay hidden forever, and to become the hero he's meant to be, Izuku will have to accept what he is: the son of a villain.
Viridescent
(AO3 link here) is an AU fanfic of My Hero Academia written by darkfire1220 (who also wrote Challenger). The story is centered around Izuku's struggle to be a hero despite being the child of one of the world's most infamous villains. Viridescent, after Apotheosis, is the most Favorited, Followed, and Reviewed My Hero Academia story on Fanfiction Dot Net.
Viridescent provides examples of:
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Tropes A to M
- Aborted Arc: After Izuku gets kidnapped by the League of Villains, the story seemed to be setting up an arc for Uraraka that would have her dealing with the fact that she was The Load during their attack at the training camp. However, the issue ends up being completely dropped after Izuku's rescue, even though she was also The Load there and didn't contribute anything to his rescue.
- Most of the mini-arcs in the Hassaikai Raid (Sun Eater vs. Yu, Toya, and Soramitsu, Eijiro and Fatgum vs. Rappa and Hekiji) get aborted in favor of an all-out brawl.
- Both the Olympus and the MVA arcs get aborted by the author due to fan backlash.
- Abusive Parents:
- Endeavor is just as much of one here as he was in the anime.
- Heat Viper clearly has no idea how to handle being a father to Izuku in the short time they spent together after he is kidnapped by the League, which culminated in him attacking his own son in a fit of rage after he is rejected in favor of All Might. He didn't intend to impale Izuku during their fight, however, and that made him suffer a massive Villainous BSoD.
- Dabi's father was apparently so bad that he finds Hisashi to have better odds at being a decent parent. And this is after the guy impaled his son on a metal pipe.
- Adaptational Angst Upgrade:
- Zigzagged. On one hand, Katsuki wasn't a bullying jackass to Izuku. On the other hand, he's lived in fear of his own power for almost his whole life in large part due to its association with his infamous father: Heat Viper.
- Inverted with Eri, who gets saved by Izuku much earlier than canon.
- Adaptational Badass:
- Besides gaining One For All, Izuku also was born with a fire Quirk called All Flare, which is one of the strongest fire Quirks on the planet. He even gains better control of One for All before meeting Gran Torino.
- Izuku's father is a powerful villain on par with All Might rather than an overseas worker.
- Adaptational Heroism: Toga expresses genuine remorse for her actions, whereas her anime/manga counterpart is thoroughly unrepentant, even referring to her actions as perfectly normal.
- Adaptational Nice Guy: Katsuki is still a jackass but his heart of gold shines through a bit more in this fic. He was also never a bully to Izuku and is pretty protective of him, to the point of Big Brother Instinct.
- Adaptational Villainy:
- Izuku's father Hisashi is not an overseas worker like in canon. He's a ruthless, infamous villain known for having destroyed an entire city during a battle with All Might.
- Moe "Burnin" Kamijinote was revealed to be this in Chapter 59. She's been helping Dabi, her boyfriend, hide from his father for years, and other heroes have been none the wiser.
- Affectionate Nickname:
- This time around, "Deku" isn't anywhere near as derogatory when it comes from Katsuki.
- Izuku is called "Izu" by Eri and Toga.
- As of Chapter 52, Eri has one of her own from Izuku: "Love bug."
- Afraid of Their Own Strength: Both Izuku and Eri are afraid of their own powers. Izuku because of how similar it is to his father (which leads to a fear of being ostracized by society), and Eri because she accidentally erased her father's existence.
- Artificial Human: Besides the Noumu, this is what Hisashi is. He's an artificial life-form called a "Chimera", created from All For One's DNA in an attempt to create a powerful new Quirk and a powerful pawn to wield it. To make matters worse for the heroes, there are five others out there, some of whom might be even stronger than him.
- Bad Powers, Good People: Having inherited his father's infamous fire Quirk, Izuku has struggled all his life coming to terms with it, wanting to use such power to become a hero instead.
- Berserk Button:
- Katsuki has several (P.A.L.s, being insulted, insulting or hurting Izuku, etc.) so it's more like a berserk switchboard.
- Don't ever kidnap Eri. If you do kidnap Eri, get as far away from her protector as you can, because by this time, this young man is furious, and he'll do whatever it takes to get his little girl back, and woe betide everyone and everything in his way, especially you.
- If your name is Kai Chisaki, however...
- All Might. Good lord, does Heat Viper hate All Might!
- When he found out that All Might passed One For All down to his son, he flew into an Unstoppable Rage, complete with him screaming All Might's name to the heavens.
- Izuku named All Might his father figure...right in front of his own father. Izuku had to have known it wasn't going to end well after that.
- Izuku really hates his father for his villainous actions as well as causing him to live a life fearing being ostracized by society for his bloodline.
- Beware the Nice Ones: Inko is one of the kindest people in the show, but her response to Overhaul trying to kidnap Eri was to nearly tear his eye out with her Quirk.
- Biblical Motifs: Both Izuku and Hisashi have demonic imagery going about them. Tomura and Endeavor refer to them as devils and they can grow flaming horns that enhance this motif.
- Big Brother Instinct: Izuku and Katsuki both develop this towards Eri. Katsuki even reins in his swearing whenever she's in earshot.
- Big "NO!": Ochako, after Izuku is successfully kidnapped by the League of Villains.
- Big, Screwed-Up Family: Izuku's extended family. His father, Hisashi, and his grandfather, All for One are villains. Izuku and Inko adopt Eri, who becomes legally part of the family later in the story. Izuku also calls Toshinori his father, much to Hisashi's rage. His cousins, well "cousins" (as they aren't really biological), the other Chimeras, include Kaiju Gigantomachia and Himiko Toga.
- Black Eyes of Evil: Whenever Viper goes all out, his eye's sclera turns pitch black with green pupils.
- Brought Down to Badass: Hisashi/Heat Viper was strong enough to knock Izuku, Pixie-Bob, and Tora unconscious, Hisashi complains how this is a sign that his years in prison have weakened him, claiming that he would have killed them (Pixie-bob and Tora, anyway) in a single-hit otherwise. All For One does not dispute this.
- Cooldown Hug:
- Curb-Stomp Battle:
- We aren't fully aware of what happened in the darkness simulation room Cementoss created other than All Might beating a full-powered Dark Shadow with a single punch.
- Subverted in Katsuki's fight with Todoroki. While it looks like Katsuki was effortlessly thrashing Shoto from the outset, in actuality, Katsuki was going all out and was severely strained after the fight. It only looks like this because he was good at hiding it while firing on all pistons.
- One moment, Katsuki and Shoto are tag-teaming against All Might for their Final Exam. The next, All Might has Shoto pinned on the ground while holding a barely conscious Katsuki by his suit wondering, "what the f*** just hit us?"
- Heat Viper delivered one to Endeavor in the past, which resulted in him needing to be saved by All Might. This is also a major reason why Endeavor despises Izuku, as he reminds him of Viper and as such his bruised ego.
- When the League of Villains invade the camp, he casually takes out any student dumb enough to get in his way, as well as Pixie-Bob and Tiger.
- He also delivers one to several pro heroes during the hideout raid, even giving another to Endeavor. Though it's acknowledged that he did last longer this time.
- A humorous example. After Katsuki steamrolled everyone in Guitar Hero, Kyoka steps in and utterly destroys all his high scores without even trying. It was so bad that Katsuki mentally went blank.
- Darker and Edgier: Combined with Bloodier and Gorier, fights tend to be more visceral than the anime or manga. Case in point, during his fight with Heat Viper, Izuku got impaled through the torso with steel pipe from a dilapidated building. Not to mention there's more frequent foul language.
- Does This Remind You of Anything?:
- Himiko's blood-lust is treated like a tragic addiction. She states that the introduction of blood to her five senses helps her cope with the trauma she received following her kidnapping, much like how an alcoholic uses said drinks to numb pain.
- Heat Viper's reaction to learning that Izuku has a "sister" implied that his thought process was that All Might moved in with "his" family.
- The Dreaded: Heat Viper is heavily feared by the entire hero community. Fighting evenly against All Might and devastating a city beforehand will do that to you. His escape puts the entire hero community on edge.
- Emerald Power: All Flare's flames are green, because the Quirk's base was Green Flare, a feeble power letting its user color fire. It's considered one of the most powerful fire Quirks in the world.
- Even Evil Has Loved Ones: Hisashi is pretty fixated on Izuku and obviously upset when the teen rejects him as his father.
- Fate Worse than Death: Chisaki gets this. He had it coming, considering he managed to piss off the good guys and the bad guys all within the same night. He seals his fate when he conspires with a Russian Crime Boss to get Eri back.
- Full-Frontal Assault: When Mineta and Kaminari had the rather bright idea to make off with Katsuki's clothes while they were in the shower, he comes after them in a Modesty Towel...until he loses that too. Thankfully, Momo beans him with an encyclopedia before he can go far.
- Groin Attack:
- Katsuki delivers an epic one to Mineta for being a pervert to the girls. It not only sent him flying over 900 meters but it also broke the sound barrier! He does this to him again during the Sports Festival. With the sound barrier breaking again as he punted Mineta into the sky.
- Kota switches it up and punts Izuku in the groin as opposed to punching him like he did in canon. He's proud of it and says as much to Izuku, later on.
- Gruesome Grandparent: All For One subjects Izuku to a brutal Training from Hell to hone his killing instincts. He even outright tells him that while he's useful, he's not invaluable. The narration also makes it clear that All For One mainly sees Izuku as a tool, not a person.
- Handicapped Badass: Besides All Might and All For One, Heat Viper's physical strength has diminished as a result of sixteen years of inactivity. Thanks to an enhancing drug, his strength is such that he can effortlessly knock out Pro Heroes with minimal effort and his durability still lets him shrug off 100% Smash attacks with barely any injury.
- Heart Is an Awesome Power: Inko's Quirk allows her to telekinetically draw small items to herself. Unfortunately for Overhaul, his eye counts.
- Heel–Face Door-Slam: Hisashi claims this was the case for him. Unsurprisingly, Izuku doesn't believe him, although he later finds out that this was actually true.
- Hero with Bad Publicity: Izuku gets this treatment after using his full power at the Sports Festival reveals his lineage to the world. He ends up becoming the outcast he always feared he'd become and while he was captured by the League of Villains, the media believed that Viper was "reclaiming" his son. This starts to become subverted after he fights Heat Viper to save All Might. While the world is still iffy about him, this heroic act that the world could not ignore effectively forced his detractors to (mostly) shut up and accept that Izuku Midoriya is going to be a hero.
- Hidden Depths: Best Jeanist is an expert field medic, even possessing a license to perform emergency surgical procedures. This came in real handy when Izuku got fatally wounded during his fight with Heat Viper and likely wouldn't have survived had Jeanist not been there.
- Horrifying the Horror: When Izuku used his Quirk on the Sludge Villain, he completely terrified him. Understandable since his father's Quirk is easily recognizable up close.
- Horned Humanoid:
- Eri and Mina. The latter even refers to them as "horn buddies".
- Whenever Izuku or his father use their flames, flaming horns protrude from their heads. With Heat Viper, they're much longer and, combined with Black Eyes of Evil, give him a demonic appearance.
- Hypocrite: Endeavor tells Katsuki that no Pro hero would be interested in an arrogant asshole like him. Yeah... like you have room to talk there Endeavor. Katsuki even mentally admits that it's good advice, but he's not accepting it because of who's giving it to him.
- I Just Want to Be Normal: Izuku feels he would be better off having been born Quirkless instead of having his father's villainous Quirk.
- Impaled with Extreme Prejudice: Downplayed. Izuku gets stuck on a protruding beam after his father blows him away, in the same area as All Might. Everyone's so horrified that the fighting stops for a few moments. Even Heat Viper can't bring himself to fight anymore, not even when Katsuki blasts him at point-blank range with everything he has.
- In Love with Your Carnage: Katsuki finds Momo to be very attractive when she's pissed off.
- Irony:
- All For One mentally notes the irony that while he is raising Tomura (Nana Shimura's grandson) to be his successor as the Symbol of Evil, All Might is raising Izuku (his own grandson) to be his successor as the Symbol of Peace.
- Despite Katsuki and Todoroki being the strongest students in Class 1-A, they were also among the students who failed the practical exam.
- Granted, it's fueled by his warped worldview, but Stain can't help but laugh at the irony that the son of one of the world's most infamous and hated villains embodies what being a true hero is all about while Tenya, the brother of a "true hero", doesn't.
- "It" Is Dehumanizing: Endeavor refuses to acknowledge either Izuku or Hisashi as human beings. He typically refers to them as monsters and outright equates Viper to the devil.
- It's All About Me: Endeavor's hatred for Izuku is rather petty. Having more to do with his bruised ego over getting curb-stomped by his father than whether or not Izuku is an actual threat.
- Jerk with a Heart of Gold: Katsuki. He's a hell of a lot nicer to Izuku in this fic, but he's still a rude, abrasive and egotistical jackass, that just happens to swear vengeance on Todoroki and Endeavor when the latter sends Izuku into a Heroic BSoD during the Sports Festival.
- Like Brother and Sister: While held captive by Hisashi, Izuku accidentally slips calling Eri his "sister" before quickly correcting himself that he thinks of her like a sister.
- Luke, I Am Your Father: Turns out, Hisashi is All For One's son (albeit through cloning his Quirk and through adoption, so the genetic relation is rather small), which means Izuku is his legal grandson.
- Made of Iron: Even after taking some Pyroclasms and a Sun Forge to the face, Endeavor still managed to pull through and recover. He was brutally injured and in dire need of medical attention, but it says a lot that he took that much of an onslaught of pain and healed up in record time when just one of those attacks knocked out every other Pro, slaughtered their police assistance, and destroyed the city all in one blast. Also, the main reason the other Pros even survived was because he got in the way to take most of the damage.
- Mama Bear: Inko may be a civilian woman but threaten her children, and she'll pull your eye straight out of your socket. She also definitely wore the pants in both of her relationships with Toshinori and Hisashi, and to this day, neither of them dared to question her authority.
- Morality Pet: Katsuki has a few:
- Izuku is the most obvious. He tends to treat him like a younger brother.
- Eri is also one of the few that he's genuinely nice to. It's telling that he's willing to tone down his cursing to borderline zero when she's around. He even gives her an affectionate pat on the head and lets her get away with stealing his breakfast.
- Over time, Momo starts to become one as well. He gives her advice and encouragement for the practical exam, considers her a badass when he considers most of his other classmates as weaklings or extras, and confides with her about his personal feelings when Heat Viper's escape put Izuku on edge.
- Muscles Are Meaningless: While Heat Viper is described as well-built, he's obviously nowhere near the physicality that All Might possesses. In spite of this, he's still strong enough to trade blows with the Symbol of Peace and durable enough to shrug off 100% smash attacks to the face. This clues the UA staff in on the fact that Hisashi isn't a normal human or was enhanced in some way. Sure enough, he's an Artificial Human that was genetically designed to have that kind of power.
Tropes N to Z
- No-Holds-Barred Beatdown: Katsuki delivers a brutal one to Todoroki in the last fight of the Sports Festival. The fight has him go all out and ends with Shoto severely wounded afterward.
- No Kill like Overkill: During the fight with Muscular, Izuku (while affected by "Zero Gravity") flings him into the ground and then has Ochako throw him behind while he activates Overdrive and spins, gathering enough momentum for 100% Hulkbuster Smash!, which sends Muscular thirty feet away while his body is half-buried in the earth.
- O.O.C. Is Serious Business:
- Jiro is able to tell that Izuku means a lot to Katsuki not just because he yelled out to him during his fight with Shoto, but also because he actually called him by his name rather than a demeaning nickname like he always does.
- Both Todoroki and Aizawa get rather concerned before Katsuki and Todoroki's match because Katsuki was acting eerily calm as he entered the arena. Even during the fight itself, he wasn't yelling at the top of his lungs like usual.
- Papa Wolf: Hisashi still loves his family, despite his villiany and their dislike of him. He even goes so far as to scare off the Shie Hassaaikai when they try to reclaim Eri.
- Person of Mass Destruction: Hisashi is extremely powerful. One of the abilities provided by All Flare is an attack that strikes with the force of a volcanic eruption! He uses this when the pros raid the Noumu facility, knocking them all out, killing the SWAT team, and destroying the city in the process.
- Pervert Revenge Mode: Izuku and Katsuki have made a habit of doing this since middle school. They hunt down P.A.L.s (Perverts At Large) and punish them accordingly. You can probably guess who their main target is at this point, can you?note
- Playing with Fire: Izuku, Heat Viper, Endeavor, and Shoto are the most obvious examples. Kirishima points out that fire Quirks are rather commonplace, though it's worth noting that none of them are anywhere near as strong as the ones listed above.
- Power Misidentification: When Izuku sees Eri's Quirk for the first time (causing a tree to completely vanish), he assumes it to be a form of molecular vaporization. It is not until it is tested in a controlled environment that the U.A. staff get a first-hand experience and notice that it does not affect inorganic matter, concluding that her quirk is time-based.
- Power Of Hate: Discussed. Shoto comments that his father probably recovered so quickly from the brutal onslaught Viper inflicted on him because of his boundless hatred toward him.
- Rage Breaking Point: Katsuki finally reaches his when Heat Viper accidentally impales Izuku on a steel pipe. Katsuki hits him point blank with an explosion big enough to send him and every villain flying into Kurogiri's warp gate and causing himself severe injuries to his arm.
- Right for the Wrong Reasons: While Endeavor's treatment of Izuku as a monster is completely unjustified and his hatred for both him and Heat Viper is for incredibly petty reasons, he isn't technically wrong about Hisashi not being human since he's actually a bio-engineered artificial life form.
- Sanity Has Advantages: Inverted. Moonfish's insanity makes him completely immune to Hitoshi's mind control due to him being in a trance-like state and not actually talking to him.
- Say My Name: Izuku uses One for All at 100% and clocks Heat Viper, sending him flying into the forest. When he recognizes the power and puts 2 and 2 together, he falls into a terrible rage and yells Toshinori's hero name into the sky.
- Ship Tease: There's plenty of this going around, the most prominent being Izuku/Ochako and Katsuki/Momo. And Izuku/Himiko in a Stockholm-based, nightmarish sort of way.
- Shout-Out: Katsuki's new cat is named T'Challa. Izuku also tends to name a lot of his Smash attacks after Marvel and D.C. Comic characters and/or references, amongst them being the Hulkbuster Smash that he used to accidentally kill Muscular, Iron Spider Smash, and Black Panther Smash.
- Sins of the Father:
- Izuku fears that if it's discovered who his father is, then he will be subjected to this trope. Sure enough, it's discovered during his fight with Shoto during the Sports Festival and he is subjected to this, with certain students and civilians treating him as if he were a villain and an anonymous student leaving a note outside the classroom door telling him to kill himself. On the day returning from the Sports Festival, there was a crowd outside that was practically demanding that UA expel Izuku just for being Heat Viper's son. Thankfully, most of Class-1A doesn't treat him any differently, though it causes some tension from a few members.
- The media also inflicts this on him while he was captured by the League of Villains. Aizawa calls them out on how idiotic this mindset is and that Izuku is nothing like his father.
- Katsuki ends up subjecting Shoto to this. His hatred for him during the Sports Festival was largely a projection of his hatred toward Endeavor, who threatened Izuku, which caused him to suffer a Heroic BSoD. In his defense, Shoto was being heavily Innocently Insensitive toward Izuku and treated him largely as a means to get back at his father.
- Izuku fears that if it's discovered who his father is, then he will be subjected to this trope. Sure enough, it's discovered during his fight with Shoto during the Sports Festival and he is subjected to this, with certain students and civilians treating him as if he were a villain and an anonymous student leaving a note outside the classroom door telling him to kill himself. On the day returning from the Sports Festival, there was a crowd outside that was practically demanding that UA expel Izuku just for being Heat Viper's son. Thankfully, most of Class-1A doesn't treat him any differently, though it causes some tension from a few members.
- Sir Swears-a-Lot:
- Katsuki, as usual, has a very filthy sense of language. Thanks to this being a fanfic without censorship issues, his foul mouth goes much further than it ever could in either the anime or manga.
- Also applies to Mitsuki. Hey, he had to get it from someone.
- Kota also is a major potty mouth. It actually unnerves the students that someone as young as Eri has a vocabulary on par with Katsuki.
- Tomura gives Katsuki some pretty fierce competition in this regard.
- Katsuki, as usual, has a very filthy sense of language. Thanks to this being a fanfic without censorship issues, his foul mouth goes much further than it ever could in either the anime or manga.
- Stockholm Syndrome: Since Himiko was around his age, Affably Evil when not too excited and potentially a way to escape, Izuku let his guard down around her. When he's finally rescued, he's disinclined to see her as a true villain, arguing she needs help.
- Story-Breaker Power: Hitoshi's brainwashing Quirk is considered by even Katsuki to be an extremely overpowered Quirk, as anyone who talks to the guy loses automatically. This is part of the reason why he was with Hagakure to fend off against Moonfish and Dark Shadow, as he probably would have ended the attack in under a minute.
- Superior Successor: Yes and no. Izuku has a very limited supply of fire and is unable to stand the heavy heat coming with the most powerful uses of All Flare, but his control is finer and he can "borrow" other fire Quirks.
- Superpower Lottery:
- Izuku really won this with his current power-set. Besides One For All, his base Quirk, All Flare, is an absurdly powerful fire quirk even without much experience. Besides enveloping himself in extremely hot green flames, it can transmute and store other flames to become stronger, and it can temporarily steal other fire quirks to add on to it. This was deliberately invoked by All For One in his numerous attempts to create extremely powerful pawns by cloning his own Quirk, and those aren't its only abilities. That's before he combines it with "One For All". This gives him the ability to emit plasma! However, these do come with drawbacks, as they can severely damage his body if he overexerts himself.
- Heat Viper has all the abilities of All Flare, barring the ability to "borrow" fire Quirks, coupled with greater experience. Due to his nature as an Artificial Human who has undergone numerous augmentations, his physical strength and durability are comparable to All Might and is able to withstand using All Flare at full power without risk of injuring himself.
- Unexpected Successor: Even the League of Villains was floored by Izuku using All Flare - because Hisashi was supposed to be sterile.
- Villainous BSoD:
- Hisashi goes into shock when he blasts Izuku into some upturned concrete and he gets impaled on a steel pipe, nearly killing him. This left him open long enough for an enraged Katsuki to blast him and every other villain into Kurogari's warp gate. Before that, he had no reservations about attacking his own son in a rage for calling Toshinori his father.
- Himiko didn't take Izuku nearly dying well, either.
- Villain with Good Publicity: Endeavor, while a hero by profession, is reviled by anyone who knows him personally. Izuku and Katsuki resist attacking him on sight multiple times.
- Villainous Rescue: When Chisaki and his goons in the Yakuza come to demand that Eri be returned to them while she is with Toshinori, Inko, Izuku, and Katsuki as they come back from buying Halloween costumes, Hisashi arrives and lays down the law: either Chisaki stays away from his family, or Hisashi will reduce him to atoms.
- "Well Done, Dad!" Guy: Hisashi wants to be a father to his son, but his unrepentant actions combined with the suffering said actions have caused Izuku and Inko to go through have pretty thoroughly burned that bridge down.
- We Used to Be Friends: Toshinori and Hisashi used to be friends and rivals back when they attended U.A. High school. These days, they're bitter enemies.
- Wham Episode:
- In Chapter 14, Izuku unveils his power for the world to see, confirming Heat Viper to be his father.
- In Chapter 20, Heat Viper escapes imprisonment, putting the entire country, and possibly the planet, on edge.
- In Chapter 24, Izuku is kidnapped by his father and the League of Villains.
- In Chapter 29, Heat Viper blasts and nearly murders Izuku after the blowback throws into onto a protruding pipe
- What Kind of Lame Power Is Heart, Anyway?: There once was a Quirk called Green Flare. It had the power to turn fire green... and that's it. When All For One saw its potential, however, he started experimenting with it by merging it with other fire Quirks. When he combined his DNA and Quirk with it, the eventual result was All Flare, the strongest fire Quirk on the planet.
- Why Did It Have to Be Snakes?: Thanks to her experiences from the Shi Hassaikai, Eri is terrified of birds. When she first saw Tokoyami, she completely froze with fear.
- The Worf Effect: Heat Viper quickly establishes how powerful he is by effortlessly bulldozing his way through Pixie-Bob, Tiger, Shoto, and Katsuki at the training camp. It's pretty much stated that the only reason they survived is because Viper is still weak after his time in prison. He later one-shots the Pros that attacked the Noumu facility with the exception being Endeavor, whom he also casually decimates.
- Worf Had the Flu: The main reason Izuku was able to hold out for so long against his father was primarily because Viper was mentally off-balanced by his son rejecting him as his father in favor of All Might.
