AN: Warning! Heavy metal action, gore, badassery and no fucks given incoming!

That World has been ravaged for uncountable cycles, by the Waves. Mysterious events where that dimension clashes with another, bringing forth hordes of unending monsters, whose sole objective is to destroy everyone and anything. Their presence anchors the eldritch distortions to the planet, allowing them to spread their influence until the World cannot hold the pressure and vanishes, teared apart by the corrupted space-time forces.

To prevent that, the World prepared a bunch of specialized Weapons, designed to strengthen their chosen Heroes, always summoned from other realities, for the defense of the World. However, even with those divine blessings, the Heroes haven't been able to discover the cause of the Waves or stop them permanently.

Not only that, the Heroes powers made them feared and respected upon the populace, not only making them akin to gods or saints but also as absolute rulers and weapons of mass destruction.

Humanity's self-destructive and power hungry nature made it so wars and political games were made around the Heroes, provoking much more death and pain than what the entirety of the Waves had made. Entire civilizations, even Heroes, falling into oblivion because of that.

[Spear Pillar theme-Pokémon]

But… what about a Hero that wasn't human but demonstrates the greatest humanity of them all?

Not a mortal, but at the same time, able to die.

Living but dying.

A god that negates being a god.

Born from shadow and reflection.

A primordial entity of destruction and rage, punished by the Father to atone for eternity, yet tasked with protecting all of Creation and its balance.

Matter and Antimatter.

Existence and Anti-Existence.

She is Everything and Nothing at the same time.

The Fundamental Contradiction.

And let me tell you…

She's the biggest motherfucker against all the other motherfuckers.

For She is GIRATINA! Absolute Lord of Antimatter! Mistress of the Distortion World! Lady of Shadows! Nightmare of the Mirrors! Queen of Gravity! The Renegade Dragon! The Third Pillar of Creation alongside the Thrones of Time and Space! Former Gandalfr of the Void! And the Last and Strongest Shield Hero to ever appear!

And She will save that messed up and fucked up world. Like it or not.

Antimatter Shield

To say that Lurolona Village was in chaos would be an understatement.

The dimensional rift up in the sky was spilling out monster after monster, making it a nightmare for any defender to fend off the sudden invasion, some of them died. Even the civilians are dying quicker.

This place has a powerful fighter, one with strength comparable to the Heroes. Unfortunately, she wasn't there right now.

At this rate, the once prosperous Demi-human town will be destroyed and bathed with the blood of its inhabitants.

However, what no one was expecting was for a black blur to come flying at supersonic speeds and crash at the middle of the pandemonium, creating a small crater.

The villagers and even a few monsters stopped because of the noise it created.

[Hellwalker - Mick Gordon - Doom (2016)]

At first, what could be seen were a pair of black wings, so dark that they resembled shadows, from which a trio of blood red claws was spotted in each, like the fangs of a demon.

When the smoke cleared, it seemed that the owner of the wings was a teenage human girl, or at least, human-like. No one saw that type of wings in a Demi-human much less a human.

Her hair was short and messy and of two color tones: beginning platinum white while ending up as golden blonde.

Her clothes were… strange to sum up. A grey leather sleeveless jacket with shorts of the same material. Striped red and black leggings ending up in grey boots with bits of golden metal at the tips and low heels. She also had golden rings in her arms serving as armlets with golden and grey spikes sprouting from them. She also wore some kind of striped red and black tunic of unknown material from where two uh… 'big bulges' are noticed.

As for weapons, discounting the wings' claws, she had a small metallic shield with a red gem at her right arm.

Her wings, somehow, melted and fused into her back. Next after, her cold red eyes looked towards the frozen participants of the battle.

It was… overwhelming. The humans and demi-humans felt some kind of powerful pressure from her, as if she was a being so much above them that they were akin to ants. While the monsters could detect with instinct alone that new entity wasn't prey but a very dangerous predator, easily the higher of the food chain.

For a few seconds no one moved, all under the powerful gaze of that higher being, who then frowned and let out a sigh.

Lifting a hand in a manner strangely reminiscing to a crossbow, numerous blue orbs materialized around her. Her pointed hand stretched in front of her.

"Bang."

[Goblin Slayer - Main Theme/Ogre Fight]

At the signal, the orbs shot towards all directions, homing in on the monsters and making them explode in gory chunks, no one of the villagers being hurt by them.

Warning: The Heroes are forbidden of using other weapons or other attacks outside their own-

"Shut up." Giratina abruptly interrupted the message window in front of her with such authority that it didn't finish texting. She lifted her shield arm, intently observing the gem. "While I agreed for the power nerfing, that doesn't mean I accepted all those ridiculous restrictions. So if you want me to defend this world, shut the fuck up and let me do this job or…" She gripped the Shield and made cracks in it. No one was able to damage a Legendary Weapon, much less one that traded offensive strength for pure defensive power. "Understood?" Now her voice was downright demonic, not helping with her red eyes ominously shining and her sclera turning momentarily black. If there was a person or monster at less than three meters of her, they would have fainted to the monstrous growth of the Pressure.

The Shield didn't respond, verbally or not, but the dragoness knew that it understood her.

"Tsk." The Pressure and her face softened to manageable levels, now replaced by an annoyed expression "For a planet a few billion years old, its defensive mechanism isn't very effective." She let out a heavier sigh "This is why you leave these things to the experts. Speaking of..."

[BFG Division (Doom 2016) - Family Jules version]

She turned her view towards the sky. The eldritch fissure letting in infinite legions of extradimensional horrors would be terrifying for even the most experienced leader or the bravest of warriors. But for Her? It was just a Tuesday.

She smirked and manifested her wings "I have work to do."

With a single beat of her ghostly appendixes and a jump, she shot herself towards the sky with strength and speed that could be attributed to godlike beasts of legends, making a mini sonic boom that nearly deafened monster and people alike.

While ascending, Giratina shot more Aura Spheres as well as Shadow Balls at the constant rain of monsters, creating a nice fireworks exhibition accompanied by a satisfying shower of guts and blood, and no living (or undying) monster was ever able to touch ground in conditions to make damage from that point onward.

She even decided to have a little more of fun and activated Dragon and Shadow Claws in all her extremities, leaving six deadly blades of ghostly and draconic energies to reap hundreds of enemies at supersonic speeds with the ease of someone using a last model lawnmower to cut the weeds of their garden.

And still firing the Shadow Balls and Aura Spheres, adding also Dragon breath to complete the godlike engine of death and destruction against a planetary dimensional apocalypse.

By the time she arrived at the breach, there was such a gap in the flow of monsters that the next batch would arrive a few minutes later than the first, less time if Giratina decided to stop using Aura Spheres which she was massively using so that their lock-on feature would leave her with time to study the anomaly all while preventing the descent of more monsters.

Warning: The Cardinal Heroes are not allowed to leave their world.

Giratina gave the Shield a resounding hit.

The Shield didn't insist.

"Interesting."

From outside the other side of the fissure, a completely black void was visible. Giratina was more than familiar with it for it is the Void between universes, an area of transition where the laws of space and time are… let's just say that they're undefined. For as weird as the Distortion World was, at least it followed a set of physical laws, loose as they are, while the Void simply didn't have those.

It can be pretty confusing, even sometimes for someone like Her.

From that view of oblivion, she saw what seemed a landscape from another world, coincidentally at another populated area.

Apparently, whoever or whatever was in charge of the phenomenon had a sadistic streak, especially with all those monsters that came from everywhere in the Void to enter both worlds.

"Now I know how so many of those things are able to enter here. Though I have to question, from which dimension are those monsters?"

This was a problem because as she knows, entire universes filled to the brink with bloodthirsty beasts are a thing. Even if they were to stop all the waves, without destroying the source or blocking it at their home, more Waves will occur.

However, she had much more pressing business, mainly, saving the town.

Returning to the ground with the same high velocities as before, she used both her superior eyesight and her space-time detection senses to bombard every ground monster that she could find. All except one that was fleeting the village.

Antimatter Shield

The Cerberus was running away as fast as it could. Its higher level and condition of Wave Monster gave it enough smarts to lead the monster horde as well as better survive to prolong the Wave. That was why when that thing made its initial volley, it prioritized itself and chose the less suicidal option.

It also had a pack of Two-Headed Dogs for protection as well as a means of propagation. If they managed to survive, they could reproduce and expand, satisfying their instincts of killing and destruction.

[Super Gore Nest Bass Boosted (Doom Eternal)]

Alas, their monstrous purposes will never be realized for a giant fireball crashed towards them, engulfing all into hellish flames. The Cerberus miraculously survived due to being outside the radius though it was still burned and sent flying dozens of meters away, depleting a lot of its HP.

"Well, well, well." A sickeningly sweet and sarcastic voice sounded out "I hoped to eliminated all of them in one shot but it seemed I failed."

The three panting heads turned towards the voice and saw the monster that single handedly obliterated every monster of its pack.

"Sorry Fido but I don't want to spend all day cleaning up an unending monster swarm so let's finish this quick, ok?" She said in an obviously unapologetic tone.

The boss, gravely hurt and with no place to run away, lunged itself towards its executioner, hoping to at least bring both of them down.

Giratina smirked.

The Cerberus suddenly stopped half jump. When the heads looked down, they observed the clawed dark wings impossibly stretching towards their chest, puncturing it. One of the claws got out, extracting its still beating heart.

The Cerberus couldn't do anything else for it was promptly tossed away like a ragdoll, dying from lack of heartbeat. Once it perished, the sky returned to normal, as if a giant breach in reality didn't happen.

Giratina sighed "I can't believe how easy it was. Then again, that was the first Wave. Maybe those are like scouts or something."

If she were in their place, she would just simply transmutate half of their planet's or sun's mass into antimatter and just watch how the matter-antimatter reactions vaporized everything.

The thing or entity that did punch a hole in this reality either didn't have enough godlike power to destroy the planet or prefered to have its minions do the dirty, much slower job of killing everyone or everything. She doubted that last one.

From what she observed from the breach, it was there to debilitate the dimensional walls of both connected worlds and make them fuse, resulting in a planetary clash of obvious cataclysmic consequences.

"Just what is their endgame? This isn't like the Heartless that would directly target the Heart of the World or the Honkai, who would extinguish civilization but try to leave the planet intact. This sounds more like that Fatherdamned Khorne, that blood obsessed son of a bitch likes to do things the most violent and destructive possible, but he would directly send his Daemons and Chaos Marines directly. Even Tzeentch. And Nyarlathotep is too subtle for this MO."

Argh! She wished some things like interdimensional invasion were as simple! Maybe she should have gone to Palkia, she has much more reach than her.

Giratina sighed. Okay. She just began doing all this Cardinal Hero shit, there will be more time to piece everything together.

"Now that I remember." She observed the heart that was still in one of her clawed wings "Wasn't the Shield able to absorb things?"

She approached the heart to the Shield, whose gem promptly deconstructed the organ into motes of light that it absorbed.

Cerberus Heart Shield obtained.

"So that's how it is then."

Apparently, each Shield had a bonus, whether in stats or skills that can be used when not equipped after equipping them for some time.

Also, it seemed like she leveled up. From Level 1 to 23. That would be absurd but coming from a Dragon Goddess that destroyed (massacred) an army of hundred of low-leveled monsters it was nothing.

All her stats augmented a lot, minus Physical Attack, with Physical and Special Defense the most.

While she was still miffed about how the Shield ignores Physical Attack development, at least the Special Attack grew, albeit not much compared to the Defenses.

And she has also to admit that as Legendary, her stats are already pretty much superior to most Pokémon, and combined with the Heroes stat bonuses, she cannot complain much. That and she could change into humanoid Origin Form to raise her Attack.

So, not knowing the limits of the Shield and wanting to take profit of it the most, she proceeded to shred the Cerberus corpse the cleanest and most complete possible. She unlocked most shields related to each individual organ, bone and tissue salvageable, including the bodily fluids, with the locked shields apparently needing more materials.

Oh, well. Like she said before, that was the beginning, now to return to the village to see if the children's parents are okay.

Wait…

The children!

Giratina's shadow unnaturally enlarged and from it, three small figures rose as if they were on an elevator. This was one of Giratina's abilities in her domain: the ability to enter pocket dimensions from shadows, especially hers, and manipulate them. She put the children there so that they would be safe, including a window where they could see all the battle!

"Are you okay?"

Rifana and Raphtalia promptly threw up (of course, all that gore at high speed...) while Keel had a face of admiration.

"That was awesome! How did you do all that?!"

"Hmph! Easy, because no one in this world is as badass as I, Giratina!" Giratina proudly boasted, happy that she had an admirer.

What?

She may not like religious followers but she at least wants to be liked. Especially with a performance showing her might in the most spectacular form possible!

Meanwhile, while Raphtalia was still throwing up, she couldn't help but think like Keel.

"The Shield Hero… is incredible!"

AN: Giratina does not give any fucks to any rule unless explained rationally for she is a rocking reasonable gal who is also, literally speaking, The Rules!

The fucking laws of physics of a single planet, even in another universe, cannot compete against the universal authority that is, Giratina!

Okay, next chapter will go about the aftermath of the First Wave (more like First of many Curbstomps), including the soon to be failed enslavement of Lurolona Village.

In this fic, Idol planned alongside the Church to kill Lord Seaetto and then send the corrupt knights and adventurers to capture the population. In fact, they killed Seaetto just an hour before the children's summoning. But because the assassin immediately fled the territory very fast, they couldn't have taken notice of the Wave happening nor Giratina single handedly winning it.

In short, while they expect a few knights, the slavers will never expect a dragon goddess-slash-Shield Hero there.

I feel bad for them… nah! They deserve it.

As for Fitoria, well, that will be quite the Dragon Ball Z-like duel.