Calem swatted through the tall grass. Even with the Max Repel he sprayed on, he had to deal with the hordes of Yamma swarming around him.
He saw the cave alongside a deep blue river, but there was a high ledge blocking it, and Calem wasn't a rock climber. So naturally, he used his clever and sarcastic mind to discover another way: he would simply surf there. "Greninja!" he called as he released the Ninja Pokémon from its Poké Ball, "you know what to do!" In a blue blur, Greninja stealthily leapt into the river. "I never get tired of this," Calem remarked as he clambered onto the back of his partner Pokémon. "Now, SURF!" Greninja shot forward like a blue bullet, swerving through the schools of Basculin.
In front of them was a powerful, steaming waterfall, but he didn't need to ascend it, he was right where he needed to be. With the falls blasting in his ears, Calem scrambled off of the Ninja Pokémon. "Greninja, return!" Calem called as his partner was transmuted into pure energy and sucked into the ball. "We'll be battling soon enough."
To the left of him was the entrance to a cave, THE cave. He slowly walked toward the cave. He knew what he was about to face, and even his overwhelming confidence couldn't stop him from trembling with each step.
Calem grabbed his Holo Caster from his bag, quickly activating it. On the other side of the conversation was Calem's friends Trevor and Serena, and Pokémon Professor Augustine Sycamore. Sycamore was the one who sent him on this little "expedition" in the first place. Trevor's goal was to complete the Pokédex, and he had completed it, for the most part, thanks to Calem. But he still needed one more mysterious data sample. That data sample just happened to be in the cave Calem was about to enter. So Sycamore had sent him to finally "catch 'em all", and Calem replied, "HECK YEAH!", but now, he was starting to regret that choice.
"What's the name of this place anyway?" asked Calem over the Holo Caster. "You're in the Pokémon Village, and the cave you see before you is called the Unknown Dungeon," Trevor replied in his usual, explanatory way. "The Pokémon you're about to encounter has only been caught by legendary Champions," he said. "So you think I'm not a legendary Champion?" Calem sarcastically replied, "I got this bro." "And by the way," stammered Trevor, "thanks for risking your life to complete my Pokédex." "And please, please, be careful!" Serena jumped in. "No prob'," replied Calem. "That's what I'm all about!"
However, Calem, the "legendary Champion" really was scared. But he still stepped into the dark abyss that was the cave entrance, and faced his fears.
As soon as he entered the cave, a chill ran down his spine. In front of him was a tall, muscular, pink, and catlike Pokémon with it's back facing Calem. A pink cat might not sound frightening, but it was. The creature's head twitched as he noticed the intruder . It slowly turned around, and let out a menacing cry, "MEW!" Calem knew he was in for a challenge.
"Go, Greninja!" Calem cried as he sent out his starter Pokémon. "Give 'em a Night Slash to remember!" Greninja bolted toward the opposing Pokémon, preparing to attack. Meanwhile, the mysterious opponent was charging an Aura Sphere. It released the sphere just as Greninja slashed the opponent in a blade of darkness, and the two super effective attacks collided in mid-air to form a powerful surge of energy. Even Calem got flattened against the small cavern wall by the incredible force. But Greninja, who had been hit by the attack head-on, got the worst of it. It was lying on the ground, injured and flinching. But the enemy Pokémon was already healing from Greninja's super effective Night Slash. "Greninja, return!" called Calem as the Ninja Pokémon was sucked into the Poké Ball once more.
"Go, Aegislash!" Calem said as the Royal Sword Pokémon appeared on the field. The opposing, catlike Pokémon quickly blasted another Aura Sphere at Aegislash. "Kings Shield!" Calem yelled as Aegislash raised its shield, stopping the opponent's attack in it's tracks. "Now use Shadow Claw!" Aegislash drew its sword and stabbed at the opponent, but the mysterious Pokémon easily blocked it with a psychic barrier, and gave Aegislash the taste of what it's like to have an Aura Sphere to the face. "Aegislash, return!" Calem said as he called back the Royal Sword Pokémon from the field and back into it's Great Ball.
That guy's powerful, Calem thought. Too powerful. I'll have to give it my all. "Charizard!" yelled Calem, "Mega Evolve and GIVE 'EM HECK!" Calem thought he saw his Charizard smirk as began it to glow. Calem's Mega Ring was also glowing as Charizard was absorbing energy from the ring, until Charizard was encased in a bright ball of energy. And then, the ball of energy exploded, revealing an almost completely different Pokémon. It looked like Charizard, but it had grown another horn, and its two previous horns were sharper. Its wingtips were more pointed as well, while its arms grew spikes, and its tail was littered with sharp ridges. It tackled the opposing Pokémon in a flurry a flames the way no normal Pokémon could've done. Charizard was gone as far as this battle went, there was only Mega Charizard. But as powerful as Mega Charizard was, the opposing Pokémon was still on it's feet. And then, it replied to Mega Charizard by an ultra powerful Aura Sphere, blasting Mega Charizard square in the stomach. "Charizard, return!" he called. The mysterious enemy was low on health, but Calem didn't think he could use an Ultra Ball on it yet, but he had a plan.
"Greninja, you got this!" Calem cried as he sent out his starter. Greninja was also low on health, but Calem knew it could do it. "Greninja, WATER SHURIKEN!" he yelled as the Ninja Pokémon sent out multiple projectiles of water at the enemy, but the mysterious opponent had a surprise too. It unleashed a powerful, psychic attack at Calem's partner Pokémon, and it blasted into with the Water Shurikens, creating an explosion that knocked both creatures back.
Greninja was out cold, but the opposing, catlike Pokémon was starting to recover. So Calem took his chances, grabbed an Ultra Ball from his bag, and threw it. He waited for those haunting five seconds, waiting for the enemy Pokémon to burst out of the ball, but it never did. And that Ultra Ball clicked, Calem knew he did an impossible thing. "Greninja, return," Calem said. "We did it."
As he walked out of the cave, he heard his Holo Caster beep. He excitedly pulled it out of his bag to hear Serena's worried voice, "Calem! Calem! Are you okay?" Calem smiled, "If you call catching like… the most powerful Pokémon in the world okay, then yeah, I'm fine!" Serena smiled as the rest of the scientists in the lab cheered, including Sycamore himself.
Meanwhile, Calem scanned the Ultra Ball with his Pokédex, "Mewtwo, the Genetic Pokémon: It was created by a scientist after years of horrific gene-splicing and DNA-engineering experiments." Calem grew a smirk, "Mew… two; really? Is there like a Mew-One or somthing?"