The child's cry was the last on Berserker's mind.
With his Master's Command Seal powering his blows, his every move was directed at one thing and one thing alone. That being…
"You persistent little—!" the beast he'd been tasked to slay roared from behind a forest of bloodthirsty insects and malformed appendages. "DIE!"
The swarm and flood of flesh spewed. However, a similar flood, one more pristine and clear and blue, rushed against it. Like a river torrent, the burst of mana washed away the impurities that sought to kill him and his Master. But it wasn't enough.
"K—Kill him! Ber… Berserker!"
Over his shoulder, the knight's crimson visor eyed the kneeling cripple for just a moment. His Master wouldn't last long. Due to the Command Seal demanding he uses his full power, he'd drawn his demonic blade. But not only was the weapon insufficient in dealing with the current threat, doing any more than holding off would continually drain his Master further.
The worms had reawakened within Kariya, but being a power lent by their foe, it was only a matter of time before the panicked amalgamation of worms and corpses realized he could just demand the insects eat his son from within.
If Kariya died, he would fail to defeat his foe. Even blinded by madness, Berserker was rational enough to understand the futility of his course of action.
"Catch, you crazed fool!" Which was why a long-barreled firearm being thrown his way was the second time Berserker was caught off-guard by the Avenger Servant.
"… Raaaaagh…" If a growl could convey confusion, this was what Berserker tried to express. But a mere glance at the woman cradling a child in a vortex of flames told him all he needed.
"By request of my Master, use this and go all out!" A cheeky grin adorned her mug as Avenger drew her katana and turned the giant swarm behind her, including the flesh covering the walls, into cinders. "Don't break my favourite toy now!"
"AGH!" Feeling more of his insects and biomass burned away, the monster howled as he so desperately tried to kill them. "DAMN YOU!"
Berserker slapped the bundle of attacking feelers aside. Turning around, he stabbed his blade before the man who summoned him. Arondight, the Unfading Light of the Lake, stood tall in front of Kariya's crumpled form.
"Berserker… what… are you doing?!" seeing him disarm himself, Kariya growled through the pain. "Don't… stop… Kill… Zouken… AGH!"
'As you wish…' were words he could never convey through the madness. Willing a small number of his own reserves into the weapon, the once-holy sword emitted a blue light before causing water to burst forth from the buried blade tip. It then swirled to life, encompassing his Master in an orb with a torrential current, protecting him from all harm. This was proven true when a sneaky tentacle aimed at the back of Kariya's head failed at stabbing through the barrier. The lake water created by the Divine Construct would not allow any invaders in its domain.
"DAMN YOU!" repeated the squirming worm monster. "DAMN YOU! DAMN YOU! DAMN YOU! DAMN YOU! DAMN YOU ALL TO HELL!"
A multitude of limbs and appendages shot forth to trap and snare Berserker where he stood. Those, he easily dodged with the grace of a ballerina as he leapt up into the air. He went so far as to use a few as footholds on his ascent further upwards. Many more, however, rushed towards the now-fallen Kariya who'd lost his balance and was breathing heavily from the drain on his mana.
But Berserker was not too concerned with the man's safety. The torrential orb tore those asunder. The demonic blade would continue to do so until it ran out of energy. And he need only finish his job and his Master could then rest. But it wasn't only that.
Someone had been kind enough to provide the magical energy to power the lumbering weapon he now held in his hands.
With his sword out of reach, his other noble phantasm was allowed to manifest once more. The darkness enveloped the multi-barreled minigun, consuming its sleek form with veins of black and bloodred curses. Upon gripping the trigger, it whirled faster than humanly possible. It was enough to elicit actual fear on the face of the monster below.
"DAMN YOU, BASTARD SON OF MIIIIINE!"
For once, the howling in response to the beast was not a growl of a knight gone mad, but that of a blazing inferno.
BRRRRRRRRRRRRRRRRRRRRRRRRRRRRR—
In the underground pit, a rain of ash and flame swallowed the beast. With the weapon in hand, Berserker directed his aim all over the place, burning away at all the swarms and tentacles that shot his way with Avenger's hellfire. Amplified by his own hatred and rage, nothing would escape. Nothing would be left alive. Nothing of the monster would survive.
"Stop it! STOOOOOOOOP!"
Under the oppressive rain of shell and flame, the walls burned as chunks of the monster was scorched away bit by bit. Part of the walls started to collapse, crushing even more of the flesh and burning it underneath the melted rubble.
"Damn you all!" The monster's main body shifted frantically as if searching for something. When its gaze landed on an unconscious figure, it made a mad dash towards it with what remained of its many limbs. "If it's going to be like his, then—!"
"RAAAAAAAAAAAAAAAAAAAAAAAAAAGH!"
Without hesitation, Berserker opened fire on the outstretched arm. The frantic grasp for another mana source was aborted as the tentacles failed to grab onto the unconscious Byakuya. Zouken howled as even more of his mana reserves were wasted in an attempt to heal the damages dealt to him.
Even as Berserker crashed onto the floor below, he continued to open fire. Burning anything that remotely was part of the creature. When that was done, he then directed full-auto fire on the mannequin that was the creature's core.
"DAMMIT! DAMMIIIIIIIT!" Without hesitation, Zouken then summoned all he had left and created a ball of debris and flesh around himself. Berserker didn't let up, letting the rounds fire on and on, tearing through the defensive blockade like it was butter. "RAAAAAAAAAAAAAAAAAAAAGH—!"
It was not until the monstrous cries of the elder wraith died down that Berserker relented his assault. What remained of the beast was nothing if not piles of remains burnt beyond recognition. Nothing but charcoal and ash.
It was over. The beast he'd been commanded to slay had been defeated.
"URG! ARRRRGH!"
A groan of pain drew the knight's attention. The swirling ball of water around Kariya dissipated. Not long after, Arondight, still planted in the floor, vanished into motes of bluish light. The mana implanted into the weapon for a short time had run out. The same could be said of the Master who was now struggling through the pain.
"Uncle Kariya!" the child who'd been saved by Avenger ran towards his pained Master. But, upon reaching him, she could only cry out, unaware of what to do. When her eyes found him, she could do nought but beg. "Please! Please, help him!"
He didn't move. He could comprehend the request to kill but maddened as he was, violence was the only thing he could truly understand. 'Helping' his own Master was beyond the cursed Knight of the Lake.
"Oy, wake up!" A slap could be heard from across the room as Avenger had made her way towards the still-sleeping Byakuya. That didn't last long as, with the strength of a Servant, a minor slap sent the man from slumber to pained waking in a matter of seconds. "Welcome back to the world of the living, coward. Get up and retrieve medicine for your little brother."
"HIII—!" panicked at first with the redheaded woman bearing down on him, it took him a few moments and a cursory glance around the burned basement before he could come to an understanding. "Y-you—?! Wha—… What of Zouken's—?!"
Not that it came with proper speech.
"Your father's dead and now your brother's at death's door. However, my Master still has a need for him and requests he be kept alive." A sneer on the woman's face was enough to elicit a scream from the cowering adult. "He would like for you to accomplish this favour. In exchange, he personally promises that I won't hurt you. Got it?"
"B-but—!" the knight felt a fearful glance his way. "What about—?!"
"If you save your brother, I doubt the tin can will have any complaints with you, no? Now move!"
Just the command alone had the man gulping, stammering, and rushing up the steps in a matter of seconds. Now that the creature's tendrils and insect swarm were reduced to nothing but dust and dirt, the binds that kept the exit sealed were easily thrown open by a man not wanting to die.
Had Berserker been sane, he would've cautioned the frantic man, maybe reassure him of no harm coming his way.
But this Berserker did not say anything. He couldn't. Instead, he was met by his fellow Servant's sharp gaze.
"I need not say this, knight, considering he's your Master. But while I'm retrieving mine, I suggest you keep your temper. For his sake, as well as the girl's."
Barely a second after saying so, Avenger herself vanished into light. Switching to spirit form, Berserker sensed her descent into the sewers. A speedy and careless rush to return to the boy he left below.
"Uncle Kariya?"
"Ugh… Sa-kura? You're… fine?"
This left the former Knight of the Round in the company of a crying girl and his suffering yet living Master. Matou Kariya, weakened by the immense strain his Servant momentarily placed on him, lay on his back against the cold stone floor. The girl they came here to save kneeled by his side, practically in her birthday suit.
"If you stay like that… you'll catch a cold…" a small cough escaped the man as he slowly but surely took off his jersey top. Ratty as it was, it served well enough as temporary apparel to the child. "If… your mother… finds out I let you catch a cold… she might tell me off…"
"Uncle…" the girl's once-blank expression shed more tears now than they had in months. "What… are you saying…? Uncle… Kariya… why are you… smiling… right now?"
"Am I?" The man, likely not realizing he was, paused. "Maybe… it's because... I'm glad."
"About what?"
"Ngh… I… fulfilled… my promise, right?"
"Promise…? Ah…"
"To 'return you to your mom and sister'… Aoi-san… and Rin-chan… They're likely… worried sick… don't you think so?"
"A-ah…" The girl couldn't reply as tears and sniffles overwhelmed her. Even more, flowed out when she felt the familiar head rub her dear uncle would often give her.
"It's alright now… Zouken… can't hurt you… anymore. Ngh!" The man's tired attempts to sit up failed when he fell back. Earning the girl's surprise and concern, she tried to help him. But being so small and exhausted as he was, she couldn't do anything but sit there with a tight grip on his inner shirt's shoulder. "We should… go get you… something to wear… You can't stay… like that—AAAGH! Urgh!"
Suddenly, his hand jumped to his gut. A silent groan escaped Kariya as pain coursed through his abdomen.
"Uncle… eh?!"
"AAAAAAAAAAAAAAAAAAAAAAAAGH!" It turned into a spasm that had him violently writhing on the floor whilst his hands scratched on his belly frantically. "UUURRRRRGH… … NGAAAAAAAAAAAAAAAHHH!"
"Uncle Kariya?! What's wrong?! What's wrong with you—?!"
"Heheh…" The girl got her answer when she heard the familiar chuckling. Only this time, it sounded quieter, as the morbid squeals of a tiny creature. "Hahahahahahahaha! AHAHAHAHAHAHAHAHAHAAA!"
"Zou… ken!" the cripple mumbled with a slight panic in his voice.
"Did you really think I will be easy a prey, KARIYAAAAAAAAAA!"
"Ngh?!" Just as the man's shoulders hitched in the sudden battle cry, Kariya's body lurched forward as he immediately crumpled into a fetal position. Teeth biting down on his lip, blood sprayed down his chin as he stifled the worst of the pangs yet. "Ah—agh?!"
Sakura didn't miss the hand attempting to grip tightly on his stomach. Something wriggled under his shirt. Something that caused blood to spray from a small puncture on his skin.
"Uncle—?!"
"GAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH!" A maddened howl was Kariya's response. It was followed by frantic scratching and rigorous attempts to claw at his own chest. It was as if something had invaded and was attempting to destroy him from the inside.
"Uncle Kariya?!" "K-Kariya?! What's going on?!"
Overlapping with the girl's panic, the elder of the Matou siblings returned. In his arms were a set of crates full to the brim with whatever recovery potions he could gather in such short notice. But on his face was fear and confusion beyond reason. But the concern was there.
Even as he cautiously kept his gaze trained on the stoic knight that didn't move despite his Master's suffering, Matou Byakuya tried his best to rush to his little brother's aid.
"O-oy! What's wrong with you—?!"
"INSIDE!" howled the suffering cripple as he kept trying to dig into his own guts. "Zouken's—NGAAAAAAAAH—He's… inside… me—Agh… Aaaaaaaaaaaaaaaaaaaaaaaaah!"
As the elder brother tore the bloody shirt open, the first thing everyone saw was the freshly bleeding perforation into Kariya's side. It was as if something the size of a thumb had eaten its way into his gut.
"So this is how you escaped my detection!" the screeching insect voice seemed to come from within the man's belly as it cried out and he groaned with pain. "To think my bugs would've been drugged to sleep…But no matter! With this, you won't survive the night!"
"That's enough!" cried the girl who'd realized what was going on. "That's enough, grandfather—!"
"SHUT YOUR MOUTH, GIRL!" Whether by instinct or force of habit, Sakura immediately obeyed the voice. Even Byakuya had flinched and fallen to his rear, backing away from his brother who stared at his own belly with contempt. "For betraying me… For ruining everything… I will make you suffer, KARIYA!"
Screeching erupted and echoed throughout the basement once more as Kariya's belly started to rupture and burst from within. For all watching, they only had their imagination to assume what must be going on. But for the Master who took on the curse of his family's magic, it was an all too familiar feeling of being eaten alive. Only this time, Zouken was planning to make him a living hive. 'Living' being a temporary state as he would soon be dead for it.
However, death didn't deter the man who had nothing else to lose.
"What… are you standing around… for?!" Through coughs of blood and internal torture, Matou Kariya cried out to the one weapon he had at his command. "I told you to kill him, BERSERKER!"
"Ngh?! You wouldn't—!"
The bugs within Kariya had no warning. Neither did Byakuya nor Sakura had as well.
In one moment, Kariya was writhing on the floor in immense pain. In the next instant, he was being held aloft by the scruff of his torn shirt's collar with Berserker raising him high above their heads. A jet-black blade that shone with bluish light appeared in his free hand.
"W-WAIT! DON'T—!"
Without any hesitation, the Servant thrust his sword through his own Master's gut. Neither care nor concern was expressed as the deed was done. Not even as the sword faded to light within Kariya's wound and a gauntlet was thrust into the gaping hole he just made.
"N-no! P-please!" the screeching and squealing continued as the black knight pulled out a little worm with a bony crust for a head. "D-don't—!" CRACK SQUASH
Without delay, the thing exploded in Berserker's clenched fist. This time for sure, the beast was dead.
"Ugh…" However, the man in his grasp still lived. A hole now existed in his stomach, but Matou Kariya lived. Had it been any other blade, or a Servant unskilled as he, the attempt to single out the parasitic heart of the wraith would've ended in his death alongside his father.
"Uhm…" a small voice coming from the girl below. "P-please… let him down… Mr Knight…"
A growl escaped the crimson-slit visors. However, despite the rage emanating from within the suit of armour, an uncharacteristic action took place. Relenting his grip, Berserker lowered his Master to the ground, allowing him to lie back gently.
For the former Knight of the Round, this was his first and last act of kindness in his maddened state. For even with his vision clouded by the chains of insanity placed upon him by his Master, he was still able to comprehend and respect the man's act of self-sacrifice.
Berserker, somewhat aware his continued presence would only burden the dying man further, decided to sleep once more. As Kariya was now, he had little time remaining. Should he wish to meet his former King on the battlefield, he would need to allow his weak Master some rest.
After receiving a surprised stare from Byakuya and a grateful nod from the crying Sakura, he vanished into his Master's shadow.