Disclaimer: I don't own Pokémon or any characters associated with the series. This is a purely recreational work.
"Going somewhere?" Darkrai flinched when it heard Giratina. For such a thick-boned creature, it certainly had the habit for appearing when it was least convenient.
"You know I never cared for Arceus's taste in décor. I need some fresh dark," the Pitch Black Pokémon replied smoothly.
Giratina was clearly less than convinced. "You'll miss the match if you go now, you know."
"Yeah, pity that…" curse those glaring red eyes, "but really? It's not going to be much of a match."
"What about Deoxys? It came pretty close last time?"
"Ah, close doesn't cut it for me." A mirror-like portal appeared before Darkrai, but before it could enter, Giratina shoved Darkrai back and came between it and its goal. But calm down, the floating shade reminded itself, now was not the time for a fight. "Is there a problem?"
"Yes, there is. I have a problem. I have a problem with being left in the dark, so to speak, and you know why. I'm not one to neither ask nor hinder you with the reciting of protocol or with my own curiosity, but I will have some form of an honest answer from you."
"Suffice to say that I am in the works of solving a very difficult problem, but the solution must remain hidden for a little while." Giratina tilted its head ever so slightly at this. "I have to go over Arceus's head this time- I could not risk delay; you of all Pokémon should be able to understand that."
Giratina was silent for a while, merely trying to read Darkrai's expression. When the Renegade Pokémon seemed satisfied with what it found- whatever it found- it resigned. "Can this solution of yours be delayed until after the fight?"
"Can you manage a sense of humor?" Darkrai itself was not very chatty or sociable to most anyone, but Giratina was even more grim and serious than the dark-type, so what could it hurt to oblige the dragon this once? It would be a short fight anyway, as Darkrai saw it.
The "room" that Mewtwo was led in to rest was very unusual, having a dream-like quality to it. As Mew described it, the room was interactive, and took on the appearance of whatever one thought would help to relax and focus the mind and body. As a result, the room took on the appearance of several scenes as Mewtwo was lay there and watched them pass; all of them appeared with great vividness and detail, seeming impossibly real, but when at length Mewtwo headed for the door, the room became blue skies and glass again.
Now then, it was time…Mewtwo played out a thousand strategies in its mind. What would be the best approach? What were its advantages, what were Arceus's advantages, and how could Mewtwo turn them against the great beast? Such were the thoughts of Mewtwo before battle- anticipating how the battle would end before it began and every detail and possibility in between beginning and end. And yet…What if there was something that Mewtwo could not anticipate? Surely there had to be- no Pokémon with a winning streak like Arceus could have gotten it without having itself a quick mind and a few tricks up its sleeves, as the saying went. Adapt. Adaption would be the key, yes. Expecting the unexpected and all that. Yes, that was it.
Or was it? A Ninetales that had found Mewtwo looking for the arena had been kind enough to lead Mewtwo to the door, and made some off remark about how intense Mewtwo's expression was. Could the fox not see it was not determination, but doubt? Arceus was ancient- even more so than Mew, and that was saying something. Did Mewtwo even stand a chance? Maybe it would be best to call the fight off, but then what would that say? Mewtwo had fought many Pokémon before, even very well-trained Pokémon before, but none of them were Arceus. Still, the experience that it learned from all those battles…it would not be without reward, surely.
The arena was empty, and so too was the pit. The Ninetales had gone off to tell Arceus that its competitor had arrived, so Mewtwo had a few last moments of silence.
The first Pokémon to arrive were all the legendaries sans Arceus, who, naturally, took the front row. Next were the other denizens of the Hall- the aforementioned "common" Pokémon, although there was a fair share of Pokémon here that were rare, if not extinct on Earth, and those that were not legendary or rare had an almost supernaturally healthy look- these Pokémon mostly chatted amongst themselves.
Last of all was Arceus, who strode through the crowd with an air of determination. Jumping over Mewtwo and landing on the other side of the arena, Arceus turned around and reared up. "Are you ready?"
"As ready as I'll ever be," Mewtwo replied.
Deoxys floated over the arena's center to begin the match; the words of its mind rang clear, "This battle is between Arceus, the Alpha Pokémon and Mewtwo, the Genetic Pokémon. No potions, elixirs, or berries may be used. May the best fighter win." Immediately after saying this, Deoxys teleported out of the pit and into the stands.
Arceus came out swinging, or charging, rather, coming at Mewtwo like a freight train. Mewtwo quickly dodged the initial trampling and evaded all but the last blow of the frenzied trampling that ensued. This was going to be tough.
In fact, it was going to be a lot tougher than Mewtwo had thought. The psychic cat tried to put distance between it and Arceus, the Alpha Pokémon reached for one of the plates that embedded onto the arena's wall, causing parts of it to turn dark grey or orange. Arceus then proceeded to cast Dark Pulse at Mewtwo, which smarted something awful. For the first few minutes of the fight, Mewtwo tried to dodge the attacks, which seemed to aggravate Arceus to no end. That isn't to say that Mewtwo wasn't irritated as well- every time that the chance came up to hit, Mewtwo was either too cautious to get close enough, or otherwise Arceus switched plates to an unfavorable type.
At some point Arceus stood its ground and roared, "Are you going to fight me or aren't you! No holding back!" Arceus's eyes began to glow bright red, and in kind, Mewtwo's became bright blue. Something clicked then for both of them as they stared at each other. For Mewtwo's part, it realized that it finally had the chance to exercise the full extent of its power- something it had not done in a long time…Now there was nothing, nothing, nothing in the world, except the opponent. What was a bloody nose when one's rival was still standing?
The fight then started in earnest. The skies cracked with lightning, the ground trembled, and from the pool water seemed to pour out as if from the ocean deep. These were two at home on the battlefield. Mewtwo hit fast and hard, relying on agility and range, when possible, while Arceus focused more on precise hitting- one strong, solid hit was worth several smaller ones and took less effort to execute. Indeed, had it not been for some careful maneuvering and well-timed Recovers, Mewtwo may well have already fainted. As it was, both combatants were tiring. Blow for blow, and neither could gain the advantage, but both could see where a well-aimed Stone Edge or a searing Flamethrower had torn at them. The arena, too, reflected the effects of the fight, being pock-marked, dented, and muddy.
Mewtwo summoned a Blizzard against a dragon-type Arceus, who launched Draco Meteor back in turn- yet…both had used Endure! Why, Mewtwo wondered to itself, did these things have to come so close? Mewtwo had been hovering, but kneeled down to the ground now, breathing heavily- were they really going to finish this? Mewtwo looked up at the roaring crowd, then at Arceus. The Alpha Pokémon had dropped all of its plates and, with shaking muscles, pawed the ground. How long had the fight been? Minutes? Hours? It did not matter- the conclusion was nigh.
In one last heave, the shower of mighty light spears that was Judgement erupted from Arceus just as a beam of psychic energy as thick as a cedar tree shot from Mewtwo. Milliseconds felt like eons, and yet before Mewtwo knew it, its vision turned white, and then black.
The first thing that Mewtwo was aware of when it came to was what a whopping headache it had. The next thing the Genetic Pokémon noticed was a Blissey tending to its wounds. "How do you feel," the pink Pokémon asked.
"Like someone dropped a Wailord on me," Mewtwo replied-and that was the truth. "What happened? Did I win or lose?"
"Neither. It was a dead-on tie. Celebi was even in the ring at that last moment and declared it so. Man, what a fight!" Mewtwo had mixed feelings about it, however. A tie? On one hand, that wasn't exactly losing, but on the other…it had poured out its blood in that fight…for a tie? Mewtwo's gaze wandered over to the other side of the ring. There was Arceus, attempting to stand up in spite of its injuries. Mewtwo tried to do the same, but both it and Arceus had to prop themselves against the arena wall for a while as Blisseys and Chanseys finished treating their wounds.
After catching their breath, both fighters staggered forward to face one another. Arceus, who had surely heard the results by now, looked to be in a giddy mood. "Thank you for a most memorable battle."
Mewtwo shook its head, "It is I who should thank you."
"Now," Arceus looked up at the audience, particularly the first row, "I myself had my doubts that a creature who was made by man could truly be as strong as I, yet see! I believe that this, Mewtwo, was greater than even its designers had known. Truly, it deserves the title of legendary." The crowd cheered, and chanted the names of both Arceus and Mewtwo.
Even amongst exaltation, though, Mewtwo felt almost humbled. Never had the psychic cat fought so hard against another Pokémon in its life- except, perhaps, against Mew, but there had been no victor in that fight, either. Far from being frustrated, it was a wonderful thing to find one's peers in strength. Not to mention- what peers they were, too!
After the excitement from the battle had died down, Mewtwo and Arceus had gone to rest. After briefly congratulating them both, it was time for Darkrai to get back to business. After gathering a few supplies, the Pitch Black Pokémon left the Hall of Origin.
This was nearly a lightless world, Shaymin considered. The only light that made its way down here were dismal flecks that came through the ceiling- and that itself was a wonder. At least there was an abundance of water here…Perhaps Shaymin could have made the effort to leave the cave, but the lack of light made the grass-type feel sluggish. Not even the Gracidea flowers that it held so close seemed to help. How long would Darkrai tell it to stay here?
As if on cue, Darkrai materialized from the shadows. "I got some things for you." Darkrai set down a bowl on the floor and next to it was something bright- the brightest thing Shaymin had seen in months. The bowl, as it turned out, was full of berries, which Shaymin gulped down greedily. "I was hoping the shiny stone might help a bit."
"It was a nice thought, Darkrai," Shaymin mumbled more glumly than the Gratitude Pokémon itself would have liked.
"You still wish to be outside, don't you?"
"I do. I'm sorry, I know you've done a lot, but I cannot live here."
"I cannot risk infection of the others."
"How do you know I am infected? I've had no symptoms, and anyway, you were as exposed as I."
"Perhaps we are immune somehow, but I have taken several precautions to ensure that I would not be a carrier."
"Could I not take those same precautions? Sooner or later every single one of them is going to be exposed to it, you know, and there's no way you can prevent that. Please, take me to the Hall, to an unoccupied room, and lock me in it, even, but I can't stay here!" Shaymin saw Darkrai hesitate, and look away. "Darkrai, I'm begging you, please! If I stay down here, I'll die!"
Darkrai sighed heavily and pondered what would be an acceptable compromise. "It need not even be so extreme. I'll take you to the Hall. Disinfect yourself, and I suppose that is as much protection I can give them. All I ask is that you do not mention my involvement prior to bringing you there. Say whatever you will, otherwise."
"Thank you, thank you!" Shaymin yipped, and gathered up its belongings, which now included a shiny stone, apparently. Shaymin had always been rather fond of those.
To make it official, Darkrai had taken Shaymin into the foyer, so that it seemed that Shaymin had come in on its own. However, Shaymin was not the only recent arrival here. Shortly after Shaymin had run off, the squadron of Dragonite spies that had been sent out into Earth to investigate the situation at large there had returned.
Of the twelve there, one called out to Darkrai, "May we proceed?"
"You may." The Dragonites kept in step behind Darkrai as it lead them to the conference room. Opening the door, Darkrai instructed them to wait here, but asked, "What news, if I may know some of it?"
"We must save the bulk of our news for the one who deployed us, but I can say this: as we flew over the world, there was a great deal of distress and chaos."