I update this chapter to make some corrections and apply the Izuku's magic style when use his teacher's Grimoire, where everyone already should notice that was inspired by UQ-Holder.
Another character from One Punch Man premiers here, which was the infamous Sound's Speed Sonic, which makes more damage than many fancy quirked villains.
The Lunch Rush cafeteria turns on a place where everyone quickly descends to mass panic, no matter the perspective of the still unknown attacker could witness, and the panic was aggravated when some students starts to kick to the others in order to run to the exit door.
Todoroki yells to warn the students to stay calm, "Please!.. Please!… Stay where you are! A strange intruder is roaming along the Yuuei campus outside!"
Iida also display his sense of leadership on sudden issues that involve potential human lives losses, "Don't panic!... Everything is fine!..."
However, many of students still punches and kicks, ending activating all their quirks, and increase the havoc to the injury. Someone needs to intervene swiftly as possible.
Izuku reacts once he clears his mind, and decide to cast, for everyone surprise and himself, the famous Somne Sign, while overcharges the Axii Sign with a combination of the Quen Sign, to increase the effect and range of the Witcher Magic, at the point to induce a lightly hypnotic wave capable to calm down the frenzy students. Izuku could not hold the Somne Sign cast more than 10 seconds with the current knowledge and training, but appears that had some effect, as several hundreds students becomes less anxious, and even some of them falls to sleep.
The younger wizard own magic energy suddenly drops due to the insensate will to manipulate all student's wills, making him moderately nauseous, making a little difficult to fell a slight relief when notice that the whole trick somehow works.
Some of the few less affected students was the brainwasher quirk user Shinsou who notice the Izuku cast of the Witcher Signs, "What ?! How he manage to… I couldn't say brainwash… It's more a mental perturbation…. Yes, how he manage to calm down everyone on this room ?! What insane type of quirk this oddly green hair student have ?!", since Shinsou was though that Izuku should have some kind of fire quirk.
But the Shinzou stupefaction will not endure so long, as suddenly, Izuku ears a hissing sound, while someone shouts, "Satsuriku Ranjin!", which means Explosive Carnage, and suddenly the windows glasses are shattered by a wave of exploding spinning discs. Luckily, Izuku cast the Quen Sign just to deflect the broken glasses by this surprise attack, given time to cast a more powerful barrier spell.
"We are under attack!", Iida yells, almost in panic. While Bakugou, Yaoyorozu and Todoroki reacts and shift his position to defend from the impending attacker.
Izuku decides to take some lessons learned recently from Sakura-sensei and made a pact with Wind or Air spirits Elementals, in order to reduce the casting time, "Spirits from Air and Wind... I'm pledge you to seal my arm as your domain... AETHER DOMINUS!", where swirls of magic wind, with a mild afterglow, swipes along the right Izuku's stretched arm.
Izuku then could cast the pretended barrier, "Aeris senex sapiens, supplex invocat pactum sacris... Terra autem aethereis meus scutum meum et tueri hostibus!...", that enables to create a magic barrier made from wind Elementals that covers the entire former shattered windows of the cafeteria, "Dryad Magic Nature Wind Shield!"
Even during the rush and panic, several students, including the astonished Shinshou, becomes mesmerized with an awry feeling that something was odd, "Now... he manipulate air ?!"
Izuku then jumps from his former position on one of lunching tables, to the entrance hall, while some of his classmates also jumps to there.
Then a fast black shadow flashes almost from nowhere, while tries to blast the magic barrier that Izuku once casts, "Bakuretsu Shuriken!", meaning Explosive Shurikens, while the foe grins maliciously and throws a swarm of shurikens that explodes on middle air, increasing the damages and panic.
Izuku reacts and casts a magic sword, "Bellatores prisca spirituum et Caelo et Terrae... Pactum meum et gladium... Dryad Magic Wind Sword!", using the same Air magic, just to be blocked by a strange young adult dressed like an ancient ninja, using his ninjato blade.
The vision of this purple and black ninja could be comical, if it wasn't the murderous intent, "So… This is the famous sorcerer that the Major told to me", and Izuku eyes widens and becomes confused about the enemy remark.
"What are you ?!", Izuku voice tone turns to be more wrathful, "And why you suddenly attack innocent students ?!"
"Sorry! My name is… Sound's Speed Sonic!", the ninja grins, and his eyes widens, "An dishonoured ninja working to my Major!"
"Sound's Speed Sonic ?!", Katsuki gasps, "WTF is that stupid name ?!"
"A rare villain with weapons!", says Yaoyorozu, while uses his Creation quirk to make a sword, "Someone here with any communication device, should warn the Pro Heroes to come here ?!", and yells to anyone with a cellphone or smarthphone to warn the Yuuei Security System.
Sonic jumps and propels around the ceiling, walls and floor, jumping and bouncing at an increasing pace, making almost impossible to follow the ninja speedy movement.
The energetic and troublemaker blond Katsuki decides to take a strike, jumping using his Explosion quirk, tempting to punch the ninja.
"Nice try...", Sonic makes a childish smile, before throw daggers against a confused Katsuki. He badly had time to regret the bad moment.
Katsuki was been hit by a swarm of kunai daggers, and lose consciousness due to the several wounds, causing alarm and cries along the nearest peers. Izuku, on meantime quickly hold him, remove the daggers, and casts a heal spell, while holds a raged face. Meanwhile Todoroki use his ice quirk to create an ice wall to protect the students.
"Hwahahaha!", shouts the malicious ninja voice, "Can you ever match the my speed ?"
Before everyone could answer, Sonic launch another swarm of Explosive Shurikens, blasting the Todoroki's ice wall, and sending several injured student against the walls, or the entrapped ones.
"What kind of quirk this insane had ?!", Iida tries to recover from the initial attack.
Izuku just finishes to remove the daggers from Katsuki, and casts another healing spell, just to avoid more blood losses.
The ninja stops on the top of Lunch Rush signboard, and laughs, "May a kind of strength power, but I don't ever care about it, since I was training since young on my secret ninja village!"
"An old-school villain...", Izuku sighs, "But how you manage to enter here, bypassing the electronic school gates ?!"
Sonic laughs, and then explains, "I just run at my sound's speed run, and it just fine!"
Izuku eyes widens, and then grits his jaws, "Oh! But it requires an insane speed..."
After all, the Sound's Speed Sonic name already answer that question, "But… A little before, a group of mass-media journalists was grouping on the school entrance..."
Some minutes earlier...
In fact, a few minutes before, a hundred journalists was waiting permission from the Yuuei to enter, since they want make some scoops, ranging from the All Might's new job as a teacher, to the new Yuuei's best promising students.
Unknown to them, a cloaked male figure appears and waits on the top of an electricity wooden pole. He could wait to the gate security guard to open the door, once the permissions are set, but it was the Sound's Speed Sonic, and "waiting" is not a word that deserves to be written on his own dictionary.
Like a mad childishness game, Sonic blasts, and use the maximum reference points, like a pole, a wall, or even a trash bin, to use the reflective momentum impact in order to increase his speed. Them, use the ninjato blade to cut, behead or slash the bodies, while runs around the journalists, who now screams in panic and tries to run, just to be killed a fraction of second latter.
The former journalists position helps Sonic to murder them in a few seconds, and them jumps and propels against a reinforced concrete wall that was almost of the opposite side of the Yuuei entrance gates, and propels at an insane speed, probably half of the speed of the sound, and pass through the gate, even it could close totally. As a bonus, Sonic, also beheads the two security guards, just before it could react. And then, Sonic could invade Yuuei without waiting.
Sonic Rampage!...
Once Sonic finish his explanation, Izuku mind switches from a bewilderment face, to a bloodthirsty rage, and a wrathful emanating aura, "How you dare to kill innocent people!", and release his fangs, "Even you won't be welcomed by the villains!", since the majority of villains also have their own ethics.
Sonic instead to answer, jumps and delivers a rotative spinning kick, "Fujinkyaku!", which means Wind Blade Kick, that breaks the Quen Sign that Izuku casts a second earlier. Even with the broken magic shield, the vampire manages to reduce the recoil impact against the floor.
The Pro Heroes receive the alarm notification and start to run to the cafeteria, expecting that no one would be killed. The fastest one was the Kamui Woods, who notice first the rogue ninja.
However, Sonic just ignores, and applies one of his finishing moves, "Ninjitsu...", and starts to side steps, until creates several after-images, "Juu Kagesou...", which means Burial of Ten Shadows, "Chisenki!", to increase the damage and makes a scatter slaughter with his ninjato blade against Izuku.
Izuku could barely react before it could receive a serious damage, "Now it's time to play more seriously!...", and then starts to use more powerful magic spells.
"Are you holding too much... Weakling!", Sonic escalates quickly.
Finally the green-haired vampire strikes hard, "Enemy foolishness! Release the Revenge of Underworld!", and cast a firestorm against every conceivable direction, "IMPELLITERI!"
The last spell that Izuku cause an huge destruction of the walls inside the cafeteria, but the quirks of Todoroki, and Momo reduce the debris impact. And also scatters and blasts Sonic against the ceiling, just to receive another Izuku's spell, since it was also wrathful, "Seek! Spirits of Lightning! Destroy! The Blood Fire of Death!...", and when Sonic prepares to escape from the crater blasted on the ceiling, Izuku cast the magic spell against him, "VOIVOD!"
The last spell blasts the armour and clothes of Sonic, where also gives an huge electric and burning shock. The almost naked ninja falls flat to the ground, while holds a belt with some weapons.
"Very well...", Sonic grins again, "And I will give a nice present to you!", as Sonic starts to run at insane speeds, "Full Frontal Attack!".
Izuku slides and delivers an ice magic spell, even it could burn his hands, due to his weakness against extreme cold, "Great Ancient King of Northern Ices, I pledge your forged Pact!", and managed to cast a stream of ice, where resembles a little the Todoroki's ice quirk, "May your enemies be annihilated by the Realm of Ice and Snow!", but Sonic swiftly managed to divert, "Extreme Zero Intense Froze Wave!", before the ice could freeze him, "BISCAYA!"
From all Izuku's classmates, Shouto was one with the most terrified face, when witness the Biscaya spell, "WTF ?! He manage to use ice techniques ?!"
For many students, the result was astonishing. They witness a powerful villain that still manages to fight using his own physical and skill forces, instead to rely on his quirk. But the green-hair student, who almost they know that was also a vampire, also display his real powers during the fight.
"This… this… monster is not normal!", said one student, "How many quirks they control ?!"
"Why he spoke non-senses about death, demons, before use their quirk ?!", other student, which appears to be a bit more rational, notice the strange requirements to Izuku cast his suppose quirk powers.
Once the whole action appears to stall due to the dangerous stand-off, finally the first Pro Hero, Kamui Woods, managed to arrive, and witness with great horror the carnage and destruction delivered by the villain and the green haired student. The utter chaos makes him fear the possible causalities from the whole fighting.
First of all, Kamui Woods tries to calm down the students, while realize that everyone was alive, once makes some questions, and makes a quick scan. Then, he could focus to catch the villain, but Sonic fires to another extreme speed run against him, and slices all wooden arms until it was about to slice the Pro Hero by half. Fortunately, Izuku manage to save him, and blast the crazy ninja to the outside, "I summon the Fiery Power Blast from the Fallen Heroes!", and hails loudly, "DAMNED!"
"How this damned hellish curse survive this ?!", said Izuku while Katsuki and Momo yells to stop, "Izuku! Please... Recover your senses!"
Even so, Sonic repeats the same carnage with The Burial of Ten Shadows, while adds Explosive Shurikens to the recipe. The ruthless of this adversary snaps Izuku, that releases all wrath he possess, while interlace his fingers of his hands, and starts to meditate, while also Katsuki snaps, and yells in pure terror, "DEKU! Do not use this!", making several students frightened to the sudden yell, and the strange pose that the vampire make:
"Oh... My Ancient Demon Servants, Guardians of Burning Marshes!... I honour your blood pact...", while the last Signs and active magic spells that Izuku casts earlier fades, and deflects some of the shrapnel that Sonic sends, "Lend your Powers, and Reduce my Enemy to Nothingness!", finally Izuku cast the dark ball against Sonic, at the precise time when he jumps into the air, and launches another sequence of attacks, "NAPALM DEATH!".
Then a giant firestorm, and poison mist explodes, blasting everything above the Yuuei Campus, like an aerial burst explosion.
"What is going on ?!", many students never witness such variety of quirks techniques been used by the same person.
Apparently, the ninja would be instantaneously killed by such explosion, but he just escaped by his own extreme speed capability, along the fact Izuku had an abnormal low magic energy output, as Izuku still recovers from the Metal Knight incident. Sonic manage to survive, Izuku as himself witness, "Damn! It just escape!", even the speedy ninja retreats with severe burns.
"WTF was that ?!", Todoroki was just witness one the best Izuku magic spells.
By other hand, Shinsou was also in state of shock, "An aerial blast created by him ?!", while imagine, "If he could use it on Sports Festival, he can kill everyone!"
Finally Aizawa arrives to the scene and witness the all confusion, and focus on the enraged and tired Izuku's face, who slams his fist against the floor, blasting an huge chunk of the marble slab.
"What's happened ?!", yells Aizawa, while slaps Izuku, who recovers his usual self, "Why you use the Dark Schneider's Grimoire Techniques inside Yuuei ?!"
Izuku snaps and answers, "Because, it was the most effective method to handle the Sound's Speed Sonic, the murderous ninja villain!", with a voice filled with wrath.
Once his own rage bursts, Izuku's face sullen. But Aizawa understands the situation. It was a tragedy. Even the infamous ninja escapes, and every student was alive, the brutal death of about a hundred journalists was unacceptable.
Shinsou ear the strange name, "WTF is a Dark Schneider's Grimoire ?!", while thinks, "But a Grimoire is something they read on some manga and anime...", and chills, "Don't mean… This green-hair vampire is a magician ?!"
And also remembers the short dialogue with him, "Vryko-Warlock", and them connect the dots, "He's a… Sorcerer!", and almost screams, but manage to avoid, "Why such dangerous thing was ever admitted to Yuuei ?!"
Several minutes later, the cafeteria was evacuated, and some of them receive psychological and medical assistance. Izuku even needs to drink a lot of cold green tea to calm down, as their anxiety was on high levels.
Once Izuku calms down, also by Aizawa own request, starts to heal the wounds and psychological traumas using the healing spells and Witcher Signs most adequate to the effect.
After all, if Izuku don't use his powers at full extent, many students could be killed, and even his colleges was afraid of him, his actions actually saved everyone from a terrible villain.
Aftermath...
The police and the media was on a frenzy about a new and mysterious villain, which don't have many known records, and also his quirk was unknown. The name, Sound's Speed Sonic, could be a comical joke, unless the fact they murder easily several journalists, and could kill scores of Yuuei students, if a monstrous and peculiar student wasn't present at the right time.
At least, the media could display it was a rare vampire student, but hides his name for safety, and many people would think that the fact a vampire along the human students, albeit the negative social discrimination, actually saved almost half of the Yuuei students from a certain death, release shock-waves along the Internet and the Hero Association, the official organism that handles the heroic activity.
Once Izuku return to his home, on the same day of the Sonic attack, her was Infinitively worried, and she couldn't calm down until receive his son safe at home.
"Why such thing happens ?!", his worrisome mother asks.
"Oh my god, mom!", Izuku sighs, "A ninja runs straight on the Yuuei entrance gates, while kills everything on his path, and then attack the cafeteria..."
"But those gates will not closed, if a strange tries to invade ?", Inko questions.
"The main problem is this person runs so fast, that the door don't have enough time to close!"
"A speed quirk ?"
"The ninja folklore portraits those villains as a very speedy stealth warriors, but this sample was insanely fast!"
"And also brings weapons..."
"They use a sword capable to murder and destroy, while also launches scores of explosives, shurinkens, and kunais..."
"That's very odd...", his mother was really shocked, "Normally, quirk users don't use weapons, since it is very redundant."
"However, if it was not my powers, including the Dark Schneider ones, probably many students would be merciless killed...", and Izuku face frowns and almost cries.
"The Yuuei Principal calls some time ago...", says Inko, "To thank you… Since you save so many innocent students..."
"But I couldn't save the journalists queuing on entrance gate..."
"Since you was eating on the cafeteria, which was you was suppose to do...", and his mother bites Izuku's neck, as a kissing compliment, "You simply can't be at two different places, and reacts at the optimal time."
"That's right, mom..."
"Take this fresh blood mixed with ginger and green tea to calm down..."
Izuku noods and drinks, even it was the second time that he had to drink bloody tea.
Two weeks later…
Almost two weeks later, about half of full magic vitality of Izuku was naturally recovered, and also was a special day, as Aizawa announce at whole class that today will go to a special training field.
"Good Morning, everyone!", Aizawa announces, "I want both of you, to go dress with your Hero Costumes, since it about 20 minutes you will be driven to a bus, which destination will be the Special Training Field, USJ!"
"Wow!", many of them exclaimed!
"It is another Hero Training Lecture...", Izuku sighs.
And everyone brings their costumes, and dress them as fast they can. Also, Izuku would bring the giant sword along him, as he, since the ninja strike, thinks that something big could be happen again.
The bus trip would take about half a hour, enough time to everyone begins to chat, and trying to pull off the moods and feelings of everyone.
"Kero...", pokes the frog quirk user Tsuyu, "Midoriya powers are terrible powerful, isn't it ?"
Everyone stare his eyes against Izuku, who stays calm and floating along his thoughts, before even dare to answer, "Beyond any reasonable scale", says Iida.
The ice and cold quirk user Todoroki frown a little before dares to speak, "Specially during the ninja incident, when he cast all fire, lightning, blizzard, wind and blasting spells against a crazy young male..."
"Oh! The Sound's Speed Sonic ninja ?", says Izuku.
"Why he had such stupid name ?!", Katsuki intervenes, with some mad mood.
"At first, all words begins with the letter S, and probably plays a quiz-game with this powers.", says Kirishima.
"But it is a very dangerous and technician skilled assassin, like the ancient ninjas could make it...", Izuku speaks with a more fainted and resentful tone.
"After all, the police couldn't find any useful information about that Sonic and even the usual villains gives a booed rejection!", says Kaminari.
"Probably it was a mercenary or a terrorist under some strong patronage", said Yuga.
Izuku snaps from his apparent frowziness, and recalls, "Mercenary ?!...", and remembers, "As you says that… He said that was working for a Major, where I don't know if it was his boss codename, or the respective military rank..."
"Military ?", Iida intervenes, "Since the quirks overtakes the average humanity, the military structure itself changes, but some countries like the Russia or South Korea, all Heroes are part of their respective army, such as the Black Ops, Special Forces or even the infantry, unlike the civilian use like our country, Japan."
"While on United States, they have civilian and military grade Heroes...", Izuku answers, "And if I born on those countries, I probably would be sent to a military academy, and life forever as soldier, with lethal force, and license to kill."
"Honestly...", Katsuki makes a wise remark, "Military Heroes are an absolute non-sense… And a total betrayal of this own concept.", and points to Izuku, "Specially, when you can live about an entire millennium, unlike the rest of us, who barely can achieve to live an entire century!", and finishes, "And living a thousand years on the battlefield, as a special soldier without get a civilian life, for me, it is outrageous..."
As everyone agrees, the moody atmosphere changes as both notice that the bus arrives on the respective destination. Aizawa also was listening their student's chatting, but he also agrees that was outrageous to force a quirk user to live as a military soldier, when the majority of them had a more law enforcement view of a hero, and acts more like a special police unit, acting under civilian regulations, than a military unit.
This remark snaps Aizawa, since his thoughts also makes sense, while remembers the same strange behavior of the Metal Knight disastrous incident. After all, Metal Knight was a soldier, and the murderous ninja behavior reveals from his demeanor that he had once a military grade training.
The entire 1-A class enter inside the huge dome that was called USJ, but once both enter the installations, the blinded door closes and shuts strangely, the main power source of electricity was cut off, and switched to the secondary systems, while some alarms activated.
Aizawa notices, from one computer screen located at the entrance hall, that an infamous skull and bonus text art appears, giving the warning sign of alarm, "Be alert! The entire USJ Security System was destroyed by a cybernetic and malware attack!"
"WTF ?! WHAT ?!", Todoroki yells astonishing, "An hacking incident, here ?!"
"This may be caused due to the same Major patronage action...", says Izuku.
Some of students rams against the wooden doors that enters the interior dome, and notice that someone already use a kind of warp quirk, and something invades from that portal. Also from outside, four black helicopters appears, in a clear coordinated attack.
Then about a hundred apparent soldiers, carrying heavy machine-guns, others some kind of rocket propelled grenades, and even laser-guide anti-tank missiles. At a first glance, the students notices that all enemies wear a Nazi insignia on their arm braces once exists the portal. Later more enemies follows the path, but appears to be like classic and opportunistic villains, where one of them was covered by hands. At last, the students made an astonished face when a kind of floating chair cast by some magic spell appears. Seated inside, was a big and fat old men, with all Nazi heraldry who just speak, "Guten Morgen! Wir sind die Millennium-Armee, die von mir geführt wird, der Major.", and change the language, "And I present two of my trustful spies..."
And then the armoured Metal Knight and the ninja Sound's Speed Sonic, along the strange faced villain reunites along their chief, "And not forget the third, which is me, the real descendant of Abigail, the Hellish Sorcerer, and the real great enemy of Dark Schneider...", and bows, "My name is Tomura!"
Then, everyone from class 1-A was in total state of shock.
To be Continued ...