History Fanfic / OldLightStillSlantsThrough

* HurtingHero: Both Tsuna and Izuku have suffered years upon years of bullying, emotional, mental, and physical trauma that continues to plague them to this day.

* NotGoodWithPeople: In this story, Izuku is generally distrustful of others due to constant bullying all throughout his life. The only ones he pours all of his trust into are his [[MommasBoy mom]], [[SpiritAdvisor Tsuna]], and [[LovedByAll All Might]]. This is why he's baffled when he realizes that he trusts Toshinori Yagi, a complete stranger, enough to completely bypass his Hyper Intuition. Uraraka's sheer, undiluted niceness to him upon their first meeting also disarms Izuku, causing him to rush to save her as he does in canon.

* NotGoodWithPeople: In this story, Izuku is generally distrustful of others due to constant bullying all throughout his life. The only ones he pours all of his trust into are his [[MommasBoy mom]], [[SpiritAdvisor Tsuna]], and [[OneHundredPercentAdorationRating All Might]]. This is why he's baffled when he realizes that he trusts Toshinori Yagi, a complete stranger, enough to completely bypass his Hyper Intuition. Uraraka's sheer, undiluted niceness to him upon their first meeting also disarms Izuku, causing him to rush to save her as he does in canon.

* SurprisinglyRealisticOutcome:
** In canon, Izuku walked off the Sludge Villain incident without a problem. In this story, Izuku was left bedridden with pneumonia for two weeks after swallowing and vomiting huge amounts of sludge and suffering minor frostbite from using Zero Point Breakthrough: First Edition. He continued to suffer from lingering effects for several weeks following the incident. He's also lost weight from his stay in the hospital, feels positively miserable and is clearly traumatized by the incident. Lampshaded by the author.
--->'''Author:''' Sorry I'm making your life suck by giving you pneumonia, Deku, but how did you escape that in canon, the dude was forcing gross-ass sludge down into your lungs, that's a recipe for a disaster if I've ever seen one, and Izuku definitely didn't get checked out by emergency personnel. I have concerns for my favorite green boy.

* RealityEnsues:
** In canon, Izuku walked off the Sludge Villain incident without a problem. In this story, Izuku was left bedridden with pneumonia for two weeks after swallowing and vomiting huge amounts of sludge and suffering minor frostbite from using Zero Point Breakthrough: First Edition. He continued to suffer from lingering effects for several weeks following the incident. He's also lost weight from his stay in the hospital, feels positively miserable and is clearly traumatized by the incident. Lampshaded by the author.
--->'''Author:''' Sorry I'm making your life suck by giving you pneumonia, Deku, but how did you escape that in canon, the dude was forcing gross-ass sludge down into your lungs, that's a recipe for a disaster if I've ever seen one, and Izuku definitely didn't get checked out by emergency personnel. I have concerns for my favorite green boy.
** Years of bad history isn't going away just because Bakugou is regretful and Izuku isn't willing to take his abuse anymore. Bakugou is torn between guilt, jealousy, and anger, and Izuku is torn between hating him and wishing he were gone and forgiving him and trying to be his friend again, because Bakugou meant that much to him. The apology Bakugou makes during the Battle Trial is a ''start'', but it's made clear by the author that it will be a long time before they're okay again, if they ever will be.

It can be read [[https://archiveofourown.org/works/13268124/chapters/30357054 here.]]

''old light still slants through'' is a {{Crossover}} {{Fanfic}} between ''Manga/MyHeroAcademia'' and ''Manga/KatekyoHitmanReborn'' written by lunarctus. It imagines Izuku as the reincarnation of Tsunayoshi Sawada, who perished 200 years ago along with the rest of the Vongola Famiglia after the rise of Quirks led to uprisings against both law enforcement and the criminal underworld. Now wielding strange flames that predate the rise of Quirks and heroism, Izuku sets off on a different path than his past life as a mafia boss, using his newfound powers to follow his long repressed dream of becoming a Hero.

* HappyEndingOverride: The Vongola Famigilia is wiped out and everyone Tsuna loves and cares about is dead in stark contrast to the light-hearted tone of his home series' ending.

* HeWhoFightsMonsters: After spending his entire life fighting murderers and other criminals to try and make the world a better place, Tsuna became so jaded after the loss of his Famigilia that he just wanted every single person who hurt him and his loved ones to die.

* RealityEnsues: In canon, Izuku walked off the Sludge Villain incident without a problem. In this story, Izuku was left bedridden with pneumonia for two weeks after swallowing and vomiting huge amounts of sludge and suffering minor frostbite from using Zero Point Breakthrough: First Edition. He continued to suffer from lingering effects for several weeks following the incident. He's also lost weight from his stay in the hospital, feels positively miserable and is clearly traumatized by the incident. Lampshaded by the author.
-->'''Author:''' Sorry I'm making your life suck by giving you pneumonia, Deku, but how did you escape that in canon, the dude was forcing gross-ass sludge down into your lungs, that's a recipe for a disaster if I've ever seen one, and Izuku definitely didn't get checked out by emergency personnel. I have concerns for my favorite green boy.

** Ochako, Midoriya's future Rain Guardian, is very light hearted and easy going like Takeshi Yamamoto. Just like him however, she is fiercely protective of her sky, Izuku, and won't let anyone hurt him. Tsuna himself notes that her flame reminds him greatly of Yamamoto. She subconciously hear Yamamoto's thoughts, and she is at least aware of Izuku being a sky without being told what dyingnwill flames actually are.

* NoExceptYes: Tsuna informs Izuku about the Vindice to convince him to not register his Dying Will Flames as a Quirk, but ultimately ends up giving the go ahead anyways after mulling over it.
** Again while discussing how Izuku has access to both Sky and Sun Flames.
-->'''Tsuna:''' They're Sun Flames. You have a dual affinity. Well — not dual. You're a Sky. You just happen to have a talent with Sun Flames, too.\\
'''Izuku:''' Isn't that the definition of duality?\\
'''Tsuna:''' [[NoYou Hush.]]\\
'''Izuku:''' ''Tsuna.''

** Before the "Heroes vs Villains" exercise, Ochako begins mentally declaring she will not let anyone take away the happiness she now has, and that she will ''kill'' anyone who tries. The implication is that as the future Rain Guardian, she is subconsciously angered at the idea of anything happening to her Sky Vongola, Izuku.

** Ochako, Midoriya's future Rain Guardian, is very light hearted and easy going like Takeshi Yamamoto. Just like him however, she is fiercely protective of her Vongola, Izuku, and won't let anyone hurt him. Tsuna himself notes that her flame reminds him greatly of Yamamoto. She also hears thoughts recalling experiences of Yamamoto's, and she somehow is aware of Izuku being the Sky Flame without being told what the flames are.

* RedemptionRejection: {{Play|ingWithATrope}}ed with. When Bakugou breaks down crying, begging Izuku to forgive him for telling Izuku to kill himself, Izuku acknowledges he's too angry and scared to forgive Bakugou, but at the least, this is a start to mending their relationship.

* {{Reincarnation}}: The central premise of the story is that Izuku is Tsuna's reincarnation, but Tsuna's consciousness is still around to mentor Izuku.

* DiedInYourArmsTonight: Tsuna's younger brother, who was only 19 at the time, died of his wounds in Tsuna's arms while trying to quell the uprisings caused by the rise of Quirks.

** This is also what lets Izuku realize that Toshinori's condition is because of some massive injury he had in the past, giving him flashbacks to what's implied to be [[ImpaledWithExtremePrejudice Chrome's final fate.]]

* SoleSurvivor: In contrast to what happened during the Future Arc of his home series, Tsuna is heavily implied to have been the last of the Vongola to fall, having watched his little brother, who was only 19 at the time, die in his arms.

** Tsuna also mused that danger and violence seemed to be how he, Xanxus and Giotto obtain their own Rain Guardians [[spoiler:moments after Izuku accidentally bonds with Uraraka]].

* GenerationXerox: Tsuna and Izuku are incredibly alike, having both experienced extensive bullying all throughout their lives, were derided as worthless and no-good, are relatively short compared to some of their peers, have MessyHair, as well as surprising potential to exceed in the roles given to them willingly or unwillingly.

* ItsAllMyFault: Izuku blames himself for putting the Sludge Villain on ice even though it was Tsuna in control, forcing both Officer Tsukauchi and Tsuna to console him about it and explain that it wasn't his fault and that he shouldn't feel bad about it to help Izuku forgive himself for his mistakes.

* KindHeartedCatLover: Izuku and his mom care for stray cats near their apartment, taking them to the local shelters after giving them some first aid and food. One of them ends up staying with the Midoriyas, with Izuku naming this cat Natsu, a CallBack to the name of his previous life's Box Weapon, not that Izuku is aware of this.

* PlayingWithFire: Izuku has inherited Tsuna's Sky Flames.

* HarmlessFreezing: Averted. Like in its home series, Zero Point Breakthrough: First Edition can cause frostbite, leaving scars all over Xanxus' body from being trapped in ice for nearly a decade and leaving Izuku's hands with minor damage despite being encased in ice for less than a minute. The Sludge Villain's unique body composition saved him from a worse fate when Izuku finally remembered to unfreeze him a few months after the incident.

* AdaptationalSuperpowerChange: Instead of becoming the inheritor of One For All, Izuku is packing Tsuna's Sky Flames, Hyper Intuition, and Hyper Dying Will Mode. He later manifests the abilities to use Sun Flames.

* HealItWithFire: Izuku learns about his ability to access Sun Flames while training for the Entrance Exam. They have the ability to improve the functionality of anything they touch, including one's natural healing ability in a manner similar to Recovery Girl's Quirk. Izuku uses this to cut down on his recovery time between training sessions and boost his strength and speed enough to manhandle the two-point and three-point robots at the Entrance Exam. He also tries to use it on Uraraka's broken ankle, but his inexperience makes it significantly less effective than a dedicated healing Quirk like Recovery Girl's, and he only uses it for immediate first aid before getting Uraraka to a licensed professional.

* MyGodWhatHaveIDone: After hearing that Izuku ended up in the hospital, Bakugou initially fears that Izuku actually took his advice and tried to kill himself. He doesn't bother him until the very end of the day, when Izuku is just so ''tired'' of their daily routine that he refuses to give Bakugou any more information about what happened, leaving him feeling somewhere between anger and guilt as he doesn't know what actually happened. He doesn't bother Izuku after that, refusing to even make eye contact with him due to his enduring belief that he almost got someone killed.

* NoExceptYes: Tsuna informs Izuku about the Vindice to convince him not to register his Dying Will Flames as a Quirk, but ultimately ends up giving the go ahead anyways after mulling over it.

* TakeAThirdOption: Without One for All, Izuku had two options for dealing with the zero-point robot. The first was to simply run away, letting Uraraka get crushed underneath (which was obviously ruled out). The second was to try and rush in and pull her out while outrunning the robot (again, implausible). So Tsuna presents Izuku with a third option: [[spoiler:Wait until the robot raises its foot into the air, throwing off its center of balance before blasting it with a full power X-Burner to total it and knock it backward so it doesn't fall on her. Aizawa was extremely impressed by this level of forethought.]]

** This is also what lets Izuku realize that Toshinori's conditions is because of some massive injury he had in the past, giving him flashbacks to what's implied to be [[ImpaledWithExtremePrejudice Chrome's final fate.]]

* StepfordSmiler: Tsuna may laugh and joke about the mafia world, but he's far from accepting of his fate and that of the Vongola Familia, having numerous mental breakdowns over the course of the story. Izuku himself also admits to being one, hiding his pain behind a fake smile so that his mom wouldn't have to worry about him.

* SugarAndIcePersonality: The story focuses far more heavily on the lasting psychological effects of being bullied all of his life, nearly dying, suffering from pneumonia, and inheriting Tsuna's GhostMemory and all the trauma that comes with it. Because of this, Izuku's personality is closer to this than his status as an overwhelming NiceGuy in canon. If you're close to him or show him kindness, he'll be a little more demure, but is basically as sweet as his canon counterpart. If you aren't, he'll treat you with indifference at best and irritation at worst. He also HatesBeingTouched and snaps at people when they're in the way of his dream to become a Hero.

* TakeAThirdOption: Without One-for-All, Izuku had three options for dealing with the zero-point robot. The first was to simply run away, letting Uraraka get crushed underneath (which was obviously ruled out). The second was to try and rush in and pull her out while outrunning the robot (again, implausible). So Tsuna presents Izuku with a third option: [[spoiler:Wait until the robot raises its foot into the air, throwing off its center of balance before blasting it with a full power X-Burner to total it and knock it backward so it doesn't fall on her. Aizawa was extremely impressed by this level of forethought.]]

* HatesBeingTouched: Years of physical abuse from Katsuki have taken their toll on Izuku here. He doesn't let anyone except for his mom and Tsuna touch him without his express permission, but he ultimately just lets Toshinori [[AffectionateGestureToTheHead ruffle his hair]] after he successfully cleared Dagobah Beach because of how close they've become over the past few months. His embarrassment and gratitude towards Uraraka for saving him from a nasty fall also causes Izuku to lower his guard as she pulls him inside.

-->'''Tsuna:'''I was the last one left. It wasn’t supposed to be like that. It was ''never'' supposed to be like that. I don’t ''care'' if they wanted me to live instead of them, ''I was supposed to protect them.'' I was their ''Sky.'' They were ''mine'', and those bastards ''took them from me—'' So I was going to try to kill them all. Damn the world. Damn fixing things. They took my family from me.

* ParentalSubstitute: Tsuna is almost a surrogate father to Izuku, gently guiding him along while also providing encouragement when necessary but keeping Izuku to a strict training regimen so he can achieve his dreams. All Might is also this, but to a lesser extent than in canon.

* SugarAndIcePersonality: The story focuses far more heavily on the lasting psychological effects of being bullied all of his life, nearly dying, suffering from pneumonia, and inheriting Tsuna's GhostMemory and all the trauma that comes with it. Because of this, Izuku's personality is closer to this than his status as an overwhelming NiceGuy in canon. If you're close to him or show him kindness, he'll be a little more demure, but is basically as sweet as his canon counterpart. If you aren't, he'll treat you with indifference at best and irritation at worst. He also HatesBeingTouched and snaps at people when they're in his way.

* CallingYourAttacks: Izuku plainly says the name of one particularly special technique when confronting the zero-pointer. [[spoiler:X-Burner.]]

* EccentricMentor: Tsuna is more than a little kooky, often getting on his protege's nerves for a quick laugh, joking about things that terrified him in the past (and freak out Izuku) and suffering from emotional breakdowns when he has a particularly painful flashback. The training he puts Izuku through is spartan-like and rigid, much like the regimen Reborn put him through, especially when Izuku is still feeling the effects of the pneumonia he suffered from the Sludge Villain attack. But in the end he cares for Izuku above all else and would like nothing more than for him to succeed and achieve his goals. Izuku might trust Tsuna with his life, but he still thinks the man is "absolutely insane".

* NervesOfSteel: Izuku's NervousWreck tendencies are suppressed by Hyper Dying Will Mode, allowing him remain completely calm even in the most stressful situations. He bolts the moment it ends, oftentimes losing his lunch in the nearest trashcan out of nervousness and fright.

'''Tsuna:''' Hush.\\

* OurGhostsAreDifferent: For all intents of purposes, Tsuna is a ghost living inside Izuku's head, mentoring him and helping him use his Dying Will Flames. He can also change his form, normally appearing in his 30s as he did before his death but unintentionally reverts back to his 14-year old self after going missing for five days. When Izuku is about to fall unconscious, Tsuna can also possess him temporarily to get him out of danger.

* TakeAThirdOption: Without One-for-All, Izuku had three options for dealing with the zero-point robot. The first was to simply run away, letting Uraraka get crushed underneath (which was obviously ruled out). The second was to try and rush in and pull her out while outrunning the robot (again, implausible). So Tsuna presents Izuku with a third option: [[spoiler:Wait until the robot raises its foot into the air, throwing off its center of balance before blasting it with a full power X-Burner to total it and knock it backward so it doesn't fall on her. Aizawa was extremely impressed by this level of pragmatism.]]

* GrandTheftMe: Izuku speculates that Tsuna could have overtaken Izuku's personality at any time, preventing "Izuku" from ever existing while Tsuna lived his life. But ultimately, Tsuna is too grief stricken of his past actions and cares for Izuku too much to even consider the possibility.

-->If Katsuki were going to say something, it would be, What the hell do you think you’re doing?\\

* ComboPlatterPowers: Izuku is able to use both Sky and Sun Flames. He can use the flames to increase his strength enough to easily punch through the heads of the Entrance Exam's robots and toss them around, blast and scorch things with fire, freeze them with Zero Point Breakthrough: First Edition, heal himself and others with his Sun Flames, and potentially fly (the author says that Tsuna is intentionally being a {{Troll}} by not telling Izuku about this last one until he absolutely needs it and to [[spoiler:[[RuleOfCool give Izuku and excuse to use the X-Burner]]]]).

* SuccessionCrisis: Tsuna is pushing Izuku to find a new set of Guardians even though they have no plans of reentering the mafia world. Izuku also flatly refuses to bond with anyone until he knows Tsuna won't be hurt by it. [[spoiler:Tsuna picks Uraraka as Izuku's first Guardian.]]