The Fourth King

Disclaimer: I do not own.

Matou Kariya did not expect, in all honesty, to summon anything that would be truly able to fundamentally solve his problems. He believed that he could save Sakura, win the Grail, but not survive, not truly deal with Zouken. He was resigned, after the agony of the Crest Worms, to being a martyr.

Matou Zouken did not for a moment truly believe Kariya would win him the grail, but indulged him anyway. It amused the ancient magus to watch the broken fool suffer to what would clearly be a terrible and pointless end. His plans for the girl were not for a moment interrupted by the possibility that maybe, just maybe, Kariya would manage to do something remarkable.

The summoning started exactly as expected. The incantations were flawless, the circle was properly aligned, the catalyst was perfectly in place.

The first sign something had gone wrong was when the Command Spells appeared on Kariya's hand. Normally, this would be expected. On the other hand, no servant appeared before them in the circle. The two stood in the room, waiting for the servant to appear.

"Worthless," Zouken spat. "Even with all the resources I spent on you, you botch everything. I guess that girl wasn't so important to you after all, if you would waste my time like this."

Kariya didn't move at all, eyes unfocused.

"Do you not hear me, incompetent? Are you actually so pathetic that you died from this?"

The younger man did not so much as twitch in recognition.

"Pheh. Such a waste of my time. I knew you were weak, but I had no idea you were this much of an embarrassment. To think that I would regret even the worms used. I had hoped to at least be entertained by this venture, but-" Zouken's voice suddenly gave out as he felt it.

The room was shaking. No, not just the room, Zouken realized. The entire mansion trembled, the presence smothering the entire complex. An energy, simultaneously primordial and new, surged through him, and with a start the old man realized he was afraid for the first time in decades.

Kariya's mouth was hanging open. Zouken felt something trickle down the inside of his pant leg.

I ASK OF YOU, ARE YOU MY MASTER?

The question was not spoken, or indeed even truly made of words. Kariya felt the sheer concept of the query rumble through him, the Crest Worms having been frozen in place by the sheer weight of the link itself. It was not like what was supposed to happen. What had gone wrong? Had he awakened some True Magic with the call, brought something on the scale of a True Ancestor to this place?

I ASK OF YOU, ARE YOU MY MASTER?

The rumbling force's return shook Kariya again, and he could feel the worms inside of him dying from the connection to something so ancient, so terrifyingly powerful. But for Sakura, he had to... he had to...

"Yes."

With that single, terrified utterance, the shaking stopped. Kariya could feel the link cementing itself, could feel something immense and monstrous and extremely not human on the other end of the link. It was waiting. He felt no name for the thing, but knew instinctively he had summoned a king. A king of what he did not know, but nothing of that scale could be anything but a king. He turned around, and saw for the first time in his life that his uncle was terrified of what had just taken place. He felt something slip out of his nose. Blood? No, it was...

Wait. How were the crest worms falling out of his body without blood? What the hell? Kariya shook his head, more worms sliding out, oddly painlessly. Considering it looked like Zouken had passed out, he'd wait for...

Zouken had passed out. Zouken was just as terrified of whatever the hell he had just summoned as he was, except Zouken didn't control it. Kariya felt a spark of hope. He could get Sakura out.

It had been only twenty-four hours since Kariya had summoned what he could only assume was Berserker, but things were looking remarkably hopeful. Somehow, it seemed the contract itself was healing him, because after about the first hour, he was pretty sure there weren't any worms left in his body. His hair was starting to resume its natural color, and he could see properly out of his left eye again.

He had gotten Sakura out without any fuss, and still hadn't heard anything from Zouken. Even better, Sakura wasn't suffering any ill effects, so Zouken hadn't activated any contingency plans, and Sakura had mentioned that the worms were awfully still and quiet when Kariya was close.

He chuckled. After so much torture for the both of them, he was hesitant to believe it had turned around so quickly, but he could feel how much healthier he was. In fact, he was pretty sure he hadn't felt this healthy before the Crest Worms were implanted in him, and yet, the weirdest part of it all was that he could still produce prana. The Servant must have had something to do with it.

Kariya still had no idea what the deal was with his Servant. He was pretty sure it was Berserker, but it definitely wasn't who he was trying to summon. Not that he was complaining, of course. He was pretty sure that if he ended up asking whoever or whatever it was to materialize, any opponent would shit themselves and give up immediately.

In fact, he thought, he should probably go back to the mansion to deal with his uncle. He was moderately surprised to realize just how much confidence he felt at the thought. Maybe a bleed-over from the weird Servant, again?

"Hey, Sakura. I'm going to drop you off with Rin for a bit, okay? I have to go take care of some business, see if I can't make the worms go away for you for good. No, don't worry, really. I've got this."

Zouken was indeed angry, seemingly having forgotten all about the mind-numbing, literally pants-shitting terror that the summoning had provoked in him. But Kariya didn't care. He felt the link burn as the old man raged.

"Hey, uncle. We never did get to see who Berserker was, did we?"

Zouken paused, then opened his mouth to say something. Kariya had already raised his hand.

"Berserker, come to me!"

In retrospect, doing that while inside the mansion was a terrible idea. With that gesture and utterance, the presence from before started to coalesce, not into a human form, but something larger. Much larger. In fact, Kariya realized faintly, the floor and ceiling were splintering to bits and his servant was showing no signs of even approaching being fully formed. When the form had expanded to hit ground level and was continuing to grow upwards, Kariya was beginning to be concerned that it wouldn't stop growing. The two Matou magi had backed up, clearing more than enough room to escape the collapsing sections of the mansion itself.

It took nearly thirty seconds in total for the thing to materialize completely. Zouken and Kariya both stared, mouths agape, at the titanic creature. That wasn't a heroic spirit.

When it looked down at him with eyes larger than cars, Zouken realized he had just soiled himself. When Kariya started laughing, Zouken realized his knees had given out, and he was now sitting in his own filth. And yet he couldn't bring himself to care about that, given what was in front of him.

"A king indeed!" Kariya managed between barks of laughter. "Truly, uncle, you've outdone yourself. The Grail has seen fit to grant me with a way to stop you forever. I don't need to get the Grail for you any more. I wish I could make you suffer for the things you did to Sakura, but this guy is going to attract way too much attention if I let him out for too long." He thrust his hand forward, and the patriarch of the Matou felt his fate being sealed.

"Berserker! DESTROY HIM!"

And with that, the King of the Monsters opened its terrible maw, and in a flash of blue, Zouken was no more. He had thought, for a moment, that his precautions would save him.

As it turns out, very little stops atomic fire breath.

Might do another chapter at some point. The other one rolling about in my head was the Caster battle, but if there's significant response, I might do more than just that.

Also, theme (remove spaces):

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