The secret weapon is the Dragon Knight Lucifer Armour DKL-01, the same of Bastard! cannon, but with some characteristics from the Hellsing cannon.
The story title, if no one catches, is an indirect reference of Mahouka Koukou no Rettousei main protagonist, Shiba Tatsuya. Essentially Izuku is the formal equivalent of a tactical mage, and when will grab (spoiler alert!) the DKL-01 his full powers will be awaken, with a mixture of Bastard/Hellsing/Mahouka styles.
Further Spoilers Alert: In this story the quirks were the result of investigations by mages, alchemists and mad scientists by the Thule Society from the Inter-Wars period (1914-1939).
Later Hitler created a unit to create magical weapons, where the experimental quirk factors should have been a genetic super-powered weapon capable to increase the divine powers of the Aryan race, with the intent to destroy the inferior races.
To achieve this end, the Nazis choose rural China, more specifically Tibet and its surroundings, just to take advantage on the chaos of the Civil War between the Japanese Imperial Army, the Mao Zedong's Communist Rebels, and Stalin's Soviet Red Army, to make the main place for experiments, and also to supposedly be the birthplace of the Aryan Race.
When the Nazi Scientists discovers that the victims infected by the quirk factors gains some powers similar to alchemy and magic instead of killing them, the project was abandoned in favour of other more destructive magic weapons.
After two hundred years, most of the world population would eventually gain superpowers, ignoring that it was originally a Nazi weapon designed for world conquest!
On an trapped corridor...
Izuku's aura was boiling inside, making his rage barely unnoticed by his so-called teammates that they also known the dire and catastrophic situation they faced. Trapped under dark tunnels of some underground base on North Korea, and lost all surprise factor due to the swift response from the enemy military, it is a matter of time to be hunted down.
All human backup soldiers was defeated and brutally killed in a matter of seconds, leaving the vampires to be the ultimate warriors, and their supernatural powers could be a real advantage, if the enemy itself was not composed exclusively by vampires.
It takes only a few seconds after the warning announcement made by Zorin in order to chase Izuku and Pip's party to face the assault rampage made some Nazi solders, probably from the infamous Letzte Bataillon refereed by the still unknown vampire leader, who throw tear gas cannisters, before fire with their heavy machine guns.
Luckily, Izuku manage to cast some magic barriers to deflect the bullets, "I hate when it happens!...", as tries to hold the barrier, "Using the Witcher Sign Quen won't be useful if...".
"Don't waste too much magic!", said Serpico in order to calm down the teen vampire, who notice is bad aggressiveness against the enemy, before takes the lead and runs at an insane speed against two fast soldiers, ending beheaded once Serpico raise his short sword and cut them.
Silver Fang also tried to hold Izuku, "Remember the key role of a wizard on a party...", making Izuku surprised and annoyed, since he didn't like the classic role of a mage, who need to stay on the centre, and layered by a circle of warriors,. Izuku recognize that Serpico and Gara had great swordsmanship, who deals to make damage against the enemy, and understands why the mages should focus on heal the warriors.
"I'm more an arcane fighter...", said Izuku, "Even I have strong magic spells..."
"Don't waste your breath on useless babbling...", Gara stares Izuku, while turn his head, "You lack endurance fighting capabilities… And during the circus shows that you barely counter the attacks at all… ", referring to the Yuuei's Sport Festival, "And your abusive display of magic are more characteristic of a standard mage, than a warrior."
"We need to find quickly a way out...", said Pip, while scan any possible exit.
Pip still mad to this bad situation, and don't make any move to help his own companions. For now, he just follow a path open when Izuku use several Damned spells to blast the doors, and take down some soldiers by surprise.
On a disclosed Laboratory...
Meanwhile, on some still unknown underground bunker block, a team of insane scientists was working on several weapons, while a group of alchemists and magicians also helps them their research. About two hours earlier of the disastrous beginning of Wild Geese operation, some trucks loaded with secretive equipment was already left the underground base, and follow to a secret location, which place are believed, by the top researchers, that was the real Lord Anthrax Headquarters.
Even still, the construction of a techno-magic weapon was time and resources consuming, leaving several spare parts, and rejected components during the long and costly development. All research was oriented by a leader scientist called, Herr Doktor, or Lord Doctor, one of The Twelve Wise Men of Europa, where still makes experiments with partial or unfinished prototypes.
"If I could create a prestigious price for the most dumbest military operation ever, the Faule Japanische Armee, would won easilly!"
"And now if they manage to explode this site, why you are playing with those forbidden material ?!", said a clocked alchemist.
The Doctor makes a strange smirk, while adjust his three-lens glasses, before explains, almost as he speaks to an imaginary audience, "If I could start, that's essentially one of my own rules: never give everything to a single patron...", and he uncovers a strange device, once removed the protective fabric, resembling an exoskeleton and a cannon, at first stance, "In reality it was one of my prototypes of an alchemical enhancing magic weaponry class devices...", and gives a better overlooking of this weapon, more than to the same imaginary audience, than the actual alchemist who's stare on the right side.
"And this is the work of a full century of research!", but the Doctor fix the last sentence, "Nein… In reality, the construction of magic weapons can be traced from the beginning of Second World War, in reality even before the First World War, when take consideration the contribution of the Thule-Gesellschaft to that field... As I knew, under direct executive order of Mein Führer Adolph Hitler, it founds and puts under direct control on charge to the ultra-secret Magische Ureinwohnerwaffe Forschungszentrum and directed by the former directors of Thule-Gesellchaft and the Ahnenerbe itself..."
"The rumors of a Magic Weapon Research Center was true after all...", the annoyed alchemist sighs, just to not listen a long monologue from his college, "And, for me, is still suspicious the resurgence of those quirks along today's human population..."
"I couldn't deny that I even take several researches about the genetics of quirks, but I never exclude that could be the by-product of some researches made by my Nation during the war..."
"The official records shows that the first quirks appears on rural China during the second half of 20th century, and just not so far from a secret Nazi laboratory mounted on the boundaries of former Tibet...", while was not so accurate, because that laboratory only functioned at the same time of the Second World War time-frame. Also, the alchemist believe the real research begins as early to the boundaries of the 19th and 20th century, by the German alchemists of the cited secret societies, and the quirks was a rejected genetic mutation weapon created by the Thule-Gesellchaft and thrown away as a plage biological weapon. Instead to destroy the Untermensch, it delivers some kind of super-natural powers to the majority of mankind on less than two centuries.
The Doctor turns a little mad, even he really don't had any idea about the quirk origins. His work on artificial vampires and magic was endured, even after the Nazi Germany defeat, since the underground Millennium Army takes the legacy.
Instead he orders to shut up, "Probably the quirks was the result of an accidental experiment made from some genuine Nazi scientists, but since I don't had any record, please don't interrupt me again… Ever!...", wailing on the last word.
The alchemist could reply hardly, but opted to stay silent, and thought to himself, "Even the quirks abilities enhanced the weaker humans, are still too weak to be ever a threat to real sorcerers, magicians and skilled alchemists…"
"And this prototype was essentially the 666th version, while some parts was derived from the 616th version, and some minor ones that I don't remember for now..."
"What's a coincidence!", the alchemist makes a smirked boldface when hears the numbers, and the fact that the final version uses spare parts of the Number of the Beast by the Catholic and Orthodox perspective, who now takes more attention to the partial functional prototype on their hands.
The strange weapon revels to be a mixture of a medieval armor, layered by dragon heads, and some futuristic characteristics, resembling some techno-punk artifacts. Some electronic devices was placed along the armor, where is functionality was still a mystery.
"You are playing a dangerous trump, essentially if the enemy laid their hands on it...", spoke the antagonizing alchemist.
"Don't worry, since I place several counter-measurements to avoid to be stolen...", the rogue scientist smiles, hiding his annoyance, "After all, this is the Dragon Knight Lucifer Armor DKL-01", and pause some seconds before resumes, "And Antrax-dono just receive the most powerful version of this weapon...", and adds, "Even the raw power delivered by the Dragon Knight Lucifer Armor DKL-01 was less than tenth of final version, already delivered to Antrax-dono... After such consideration, this prototype lacks the Sword of Hell, which we don't have none, since it needed to be created according to an alchemical and dark magic ritual... Instead the Rings of Satan was already crafted, and enchanted yesterday.", but almost forgot a third item, "And speaking about unfinished items, but almost crafted, was this huge shield, placed on the other side of this facilities, the Judas Pain Shield..."
The alchemist tried to reply, but decide to not spoke, "If the enemy had really a sorcerer, it won't take more than few minutes to fill the remaining items, and activate this dangerous armor."
Instead spokes a fake excited remark, "Fortunately, you never forget anything behind...", and the real though, "What a joke..."
"Well, if those unwanted visitors don't strike today, I could ended this prototype at the next week!..."
The alchemist barely had time to think, in order to reply the conversation, since the evacuation alarm was triggered in order to the staff return to the more safest bunkers.
"For all priorities, why I need to evacuate ?!"
"The emergency may be serious...", as the alchemist was already suspected that the real enemy won't be trivial to defeat.
Meanwhile at Wild Geese place of action...
About several tunnels away, the fight between the vampires against the rogue Nazi soldiers continues deadly, leaving them dangerously wounded. Even a vampire could endure wounds that could be lethal to humans, with a quirk or not, the major problem was to run away from the enemy base, when all tunnel exits are filled with enemies, and apparently with an infinite supply of reinforcements on demand.
Izuku, who was escaped with minor injuries due to the shielding tactic, decide to apply more summoning magic in order to increase the firepower of his so-called team party.
"Sanctus aqua spiritibus, fons vitae et de septem custos maria meum et vocavi te antiquis foedus meum et illius annulo signatæ potestatem divinam.", while Izuku makes a pact to Water Spirits, in order to increase his affinity with Water Elementals.
"Why you are wasting your powers to a Elemental Magic that you don't had real affinity ?!", Pip Bernadotte was annoyed.
"Holy Saint Water, grant to me your powers! ACQUA AGER!", making Izuku surrounded by a water mist.
"Why you don't make a pact with Fire or Dark Magic ?!", Silver Fang was also a little surprised.
"Shut up!", said Izuku, "This is a Ritual to summon this thing...", as Izuku begins to imitate the movement of an unnamed kung-fu martial arts, "Bernando... Waluta… Werna… Richardo... Old Water Domain… Fill my soul!", just in time to punch his water covered fist against the floor, opening a portal, "My enemy is your enemy! May the strings of Spirits, and the damnation of Lies been my staff, and bring the Water dragon from the Underground!", summoning a water dragon, which resembles the ancient Chinese ones, "Water Emperor's Dragon Cascade! AXIS!"
"What's pure stupidity!", Pip grits his sharp teeth, "Summoning dragons just to destroy smaller targets will deplete your magic energy...", and choke before concludes, "It will drain out our magic too quickly, leaving no more energy to handle a real threat !"
"I don't care...", Izuku makes a cold stare, and hisses.
But other vampires scolds the younger one, "Don't be childish just to appraise to yourself.", specially the Silver Fang, "If you have more magic affinity to fire than water, just use fire spells… Otherwise you are wasting two, five or even twenty times more magic without real benefit… After all, your magic teacher never warn you about this ?!"
"Please, never bring Sakura-sensei when is not needed!", Izuku answer boldly.
All vampires don't answer to reply, since understand who was that person, "Whatever..."
And just when Izuku tries to end the scolding, Pip witness the next wave of soldiers running against them in order to trap. However, much of the new soldiers, when witness the new abnormality, stall several seconds to face the strange new dragon. The stand off takes several seconds, that for someone could judge that takes several minutes, until one of the soldiers decides to fire, just for Izuku command the dragon to counter-attack, "AXIS! Under my Domain I command you to Strike!", just for the dragon blast several high pressurized water streams, "Ryuukou Suiryuu!", as Izuku reads the Kanji ideograms 龍皇水流, meaning Dragon Emperor Water Stream!
It was the strong water pressure released magically by the dragon that either cuts the vampire soldiers by half, or opens holes on their torsos, before being dismembered, and throw into pieces against another like projectiles.
However, the real Izuku's objective was to use the water stream to evaluate if the floors or the ground was actually solid, and the carnage of destruction leave some unexpected sag on the floor covered by destroyed soldiers, "My bet was right...", said Izuku while the dragon dissolves, since summoned dragons rarely stay more than 40 seconds, "There's a fault under this room..."
"You mean… A secret passage ?", Silver Fang dare to ask.
" Probably… Just wait...", as Izuku now cast another magic spell, "Legions of Ruby Ray… Flesh rotten, consumed by Death!...", as Izuku casted magic forms a giant blob of fire, while releases an acidic haze, that make everything on contact to be spontaneously combusted and melts due to the extreme acidity, "May this deathly Curse burns the Enemy, and return to Water!", and when the magic spell was fully released, the ground melts and burns at higher temperatures, "ACID DRINKER!"
The affected ground almost was reduced to hot magma, but collapses before the acidic smog and heat melts and kills everyone on the room, opening a vertical pit instead that appears to connect to something else.
The last vampire of the group, and less talking of them, Regis Terzieff-Godefroy decide to intervene, "Young Vampire! Hold a minute… I will cool down the opening...", making Izuku a little surprised.
"I will appreciate it...", said Izuku, still curious.
"Alte treue Geister der Winterwälder, ich erbitte deinen Willen und deine Künste.", the vampire Terzieff-Godefroy always made is own incantations on German, making Izuku very perplexed. The incantation formula was based on the ancient ice Elementals living of old German forests during the cold winters, and use this powers to freeze the opened tunnel, "Bitte hilf mir, meinen Weg zu öffnen.", and was succeeded to do so, "Friere diesen Albtraumpfad ein und öffne meinen Weg!", and name his magic spell, "Phantom Eisschwert!"
Regis magic spell is called Phantom Ice Swords, since it manipulates spirits of deceased Teutonic heroic warriors that once lives and battles on long winters.
"Before thanks him...", Serpico intervenes, "He was the person responsible to support our group during own missions, due to his magic abilities..."
"At least, we can now escape from this trap!", at the end, Pip Bernadotte was just appreciate and use the other's works.
As everyone jumps and slides along the freezing steep slopes, Izuku stays around the opened hole, just to stay alert, as another wave of soldiers could rampage before himself could escape.
"Be fast!", said Izuku, who ear several footsteps, and rattling approaching at higher speeds, since the vampires can run as fast like sports cars, as Izuku already made the same, "We have more company..."
The elder vampires was the last ones to escape, except Izuku himself, who notice the swift reaction of the enemy, who don't waste time to raise all machine guns against him. One of the soldiers, who appears to be an higher ranking officer, had just ordered, "Töte diesen Bastard!"
Since some soldiers even bring and arm rocket propelled grenades that appears to be the same models of the Germany used at the Second World War, "Why they still use Panzerfaust ?!", they follow the officer order to fire several grenades, sending all of them like an artillery barrage.
Izuku barely had time to dodge, and casts a Witcher Sign to avoid a direct hit, as the Aard almost failed to destroy or deflect the projectiles.
Finally the green haired vampire jumps to the opened hole, once the first barrage ends, and casts another magic spell, "Oh... My Ancient Demon Servants, Guardians of Burning Marshes!", as this spell opens several portals from Hell, in order to leak the destructive firestorms from the Underworld, "Lend your Powers, and Reduce my Enemy to Nothingness!", and the thermal shock cause several explosions that kills everything on their path, specially on a closed room, "NAPALM DEATH!"
The huge explosion cause a dangerous landslide of fragments of ice, created by Terzieff-Godefroy magic spell, and chunks of store, concrete and melted iron, against Izuku who lose his foot and slides into a dark hole, slamming his body against an hardened concrete bottom of a kind of cave, just before the explosions reaches the interior of the opened pit. It appears that Izuku manage to open a vertical shaft, even unstable, to a deeper bunker than the previous one.
Hit the Jackpot...
However, the uncontrolled impact against floor, make a contusion on Izuku's head, and lose partially own senses.
Some minutes later, all Wild Geese members manage to awake Izuku:
"Are you alright ?!", said Pip, "You almost lost your consciousness...".
"Where we are ?!", Izuku was still a little headache.
"It's the entrance of some prison...", said Serpico.
A few seconds later Silver Fang yells, "It appears that Izuku gains the jackpot..."
"Why would said that ?!", Izuku was confused, "Ouch… My head..."
"I just blast with my punch, the bars of this peculiar cell...", as the older vampire grabs a barely conscious men, "The infamous Pro Hero Endeavor was been maintained captive here..."
The discovery was astonishing, since by a string of luck, they manage to accomplish a secondary mission, that was to find Endeavor, and rescue him.
"Unfortunately, all medical backup was lost...", Pip snaps that unfriendly remark, "And what bastard could leave such so-called Strongest Hero wannabe into this terrible state… After all, it's just a buffoon that thought that could fight against a real though guy", and ever he couldn't avoid such remark, "Even Sylvester Stallone or Arnold Schwarzenegger was much better than this clown!"
"One a minute!", Gara intervene, "When I read Midoriya's profile during the flight, I notice that he learn some healing magic, like Terzieff-Godefroy that had some magical medicine knowledge."
"It's right, but...", again Pip counteracts with their arguments, "We, vampires, cannot be skillful on Healing Magic, since all healing mages require to master White Magic in order to work correctly, and Midoriya, like the rest of us, are by nature, Black Magic sorcerers!"
Izuku frowns with this cruel remark, that even agrees, but the reality is not a bipolar black and white:
"Even so… We have two companions with an weak capability to make some White Magic, in order to make some very basic healing magic spells.", said Gara again.
"It's better for them to treat Endeavor, even it has just a first-aid...", Silver Fang agrees.
Izuku was disgusted to the severity of wounds and the dry blood that coats the remaining of their shattered costume. The green haired vampire also noticed a strange magic flow along Endeavor's body, just in time that Terzieff-Godofroy notices the same:
"This men had their so-called quirk sealed by a Black Magic spell, Dark Schneider..."
"That's right…", and he was frightened by the faded runes, "But… OMFG! Look at those cursed runes!… The person who defeated Endeavor and applied such magic spell should at least a rank comparable to me… It's almost the Accused magic spell that cast against the invaders on the Yuuei's Sports Festival...", and almost choke with pain, "Even I was terrible mad to everyone on such day, I just kill them by using such forbidden spell...", just he was deeply worried to such wrongdoings.
"My healing abilities are beyond to reverse such terrible thing… But you know any kind of anti-magic or reverse-magic spell ?"
"Even the Accused spell require some strong counter-magic to be dispelled… However...", as Izuku grabs his smartphone, and opens a digital scan of his own Grimoires.
It takes several seconds, exceeding more than one minute, but Izuku managed to find a solution, "It requires to use two spells simultaneously, but you should stay alert to finishes the healing..."
"Fine!", the elder vampire holds the unconsciousness Endeavor in order to avoid problems.
"Mediocris naturae spirituum... Ingens scientia antiquorum sapientum... Peto auxilium tuum...", as Izuku itself shines, and forms a magic circle that encircles him, Terzieff-Godefroy and Endeavor inside, "Magia antiquis Elymas magus omnium artium, hoc oro ad victimam, et curabo eum omnis maleficence!"
Suddenly, a strong explosion from Endeavor own body propels the mages duo away, while a glooming aura was released, that also contributes to blast Izuku and the older vampire away a few meters, "Damn it!"
"We fail ?", and the elder was worried.
"It appear that this cursing spell share the same common characteristics of my Dark Chaos of Destruction Magic, even it was slightly different...", and notice that the cursed aura was diminishing.
Pip sighed, "It appears that you need to wait until a real skillful medical sorcerer could handle this case..."
Izuku smiles, "Now!… Terzieff-Godefroy!… When I cast the following spell, use your basic healing magic you can use!..."
Pip was shocked, specially when the older vampire nods, "I'm ready..."
"Ellen… Collen… Allen… Savage… I summon and pledge my Heroic Heroes of War!...", and Izuku holds about a meter from him, and above Endeavor, a black lightning ball of energy, quickly collapsing like a black hole, "I request your mystic symbol's fire and lend me to let Love and Hate collide!", making the cursing spell energy to be sucked by this strange black hole, "Archaic Black Liquid Lightning Sphere, purify them all!", and once Izuku finishes the incantation formula, Endeavor awakes with great pain, releasing blood, while the runes breaks, and the dark curse flows to the black hole, "DEF LEPPARD!"
"MIDORIYA! That's totally stupid!", Pip panics when saw an injured human choke blood, and releasing the curse seal with almost no real control, "You could kill him!"
"It's now your… turn!...", said Izuku, while fighting to hold himself the confrontation of his magic with the foreign vitality flow curse, as the black bolt explodes, and releases a devastating explosion that cause the fall of debris along the improvised prison.
"Alte Heilgeister aus fernen vergessenen Königreichen …", quickly the older vampire puts his right hand over the shaking Endeavor's body, and this starts to glow, "Ich bitte um deine Weisheit und deinen Willen ...", and starts to heal partially the wounds, while drain the remaining of all dark miasma leftovers, "Bitte hilf mir, diese Männer zu heilen und ihn von allen schlechten Omen zu befreien ...", making the minimum necessary to calm him down, "Phantomheiler!"
Endeavor loses his consciousness again, but Regis managed to break the cursing spell somehow, before Pip yells when notice that Izuku and Terzieff-Godefrey collapses due to exhaustion.
"Why you are so stupid ?!", Pip Bernadotte was frustrated, "I told earlier that using magic outside Black Magic domain was too costly, and using forced Healing Magic, a diametrical opposite of it, would be pure stupidity!… And now are too fainted to resume the main mission!"
A few seconds later, Izuku delivers a strong punch against Pip, "Shut up!", and yells, "I will be fine in a matter of minutes… Just a little rest I need before continues… Endeavor is now fine, since I just applied the first-aid… Now let's find the so-called secret weapon..."
Suddenly, Gara warns everyone, "This dark aura… Be careful!… Someone is arriving!..."
In a matter of two seconds, if really takes too long, every vampire grabs Endeavor and flee to random positions, just in time to avoid the swing of a scythe delivered by a demon vampire, where my everyone surprise was a woman vampire with a mad look, and a menacing aura.
"Seit wann hast du die Erlaubnis, meine Sachen wegzunehmen?", as she's annoyed to the Endeavor rescue act.
At the same time, Endeavor manage to spoke a faint remark, "That… monster… was the one… who kidnap me… Zorin Blitz!", before lose his consciousness again.
"What?! She's Zorin Blitz ?! A top commander of the enemy army ?!"
And the enemy commander just said a derogatory remark, "Wenn es nicht der berühmte Dark Schneider ist ... Ich hätte nie erwartet, ein Dieb zu sein ...", and she raise her scythe again.
"It appears that she's the first real adversary he must face...", Izuku quickly concludes his own analysis of this dangerous situation.
After all, Izuku's own intuition, and quickly nodded by everyone, was right, since Zorin swiftly makes her first strike, just to Gara block the scythe movement with his Murasame sword.
This act marks the beginning of a dangerous duel of Izuku and the Wild Gesse, against a dangerous single vampire, who already know that she had powerful magic powers.
To be Continued...