This one will definitely be something of a departure for what I've written so far. If I do do a complete story of this, it will be the first Pokémon story I do. Yeesh.

Anyway, this one was inspired by one of mellra's challenges, one where Mewtwo escapes from the lab shortly after AmberTwo's death, and ends up in Pallet, meeting a younger Ash, and becoming part of the Ketchums. Unlike the sample chapter given, as well as mysteryfandsomsareblue's Mewted, Mewtwo isn't a childish innocent abroad, nor is he going to be Ash's Pokémon. Instead, he's going to be travelling with Ash as a Pokémon researcher in the field, working for Oak, as part of his desire to discover more about himself (the title is Greek for 'know thyself'). He's also basically the Sasuke to Ash's Naruto, and when I say that, I mean in a good way. Mewtwo will be broody and cynical beyond his years (partly due to finding out his purpose from his creators as he broke free), but he is far better than how he was in his debut in the movie, and while he will want revenge against Team Rocket, he's not as obsessed with it as Sasuke is, partly because he has had Ash, Delia, and Oak as moral compasses. Mewtwo will act as Ash's voice of reason, while Ash will act as Mewtwo's heart.

So, I hope you enjoy.

GNOTHI SEAUTON

CHAPTER 1:

THE BEGINNING

My dearest sister,

As always, I hope that there's some plane of existence where you still exist, along with the others, and that this missive reaches you. I guess hope springs eternal. The Professor, for all his knowledge, can't even tell me whether there is an afterlife. Only Arceus knows, I'm sure.

In any case, tomorrow's the day. I've spent four years now in Pallet. Four years as part of a family. To the rest of the town, and the world in general, I am Cole Ketchum(1). Only Ash, Delia, and the Professor know who and what I am. Even Ash, bless his indiscreet little heart, has kept the secret. I've said it before, and I'll say it again, you'd like him. He's not the brightest of kids, and he has a tendency to rush off into danger when I'm not around to stop him. But he has a good heart, and his determination is boundless.

Tomorrow's the day when Ash is able to become a Pokémon trainer. So too will the Professor's grandson. I've never been able to get along with him: how the Professor has a grandson like that arrogant brat, I'll never know. Seriously, he has his own fanclub, somehow, and in a small town like Pallet, too. Anyway, I'll be heading out with Ash. I'm becoming a field researcher on Pokémon. Yeah, it sounds weird, researching my own kind. But I feel this is my path. There's the old saying, gnothi seauton. Know yourself. And I still do not know myself, even as I learn more about myself and the world.

I am both unique, and not. I straddle the line between Pokémon and human. I am powerful, and yet, there are those who seek to harness my power. Team Rocket is still out there, along with the man who hired your father. The man who ordered my creation, so that he could create his own personal weapon. I refuse to allow him to dictate the purpose of my existence, my dear sister. I may hide for now, but should he or his underlings threaten me and mine, he will regret it.

I can still hear Ash watching the battles on TV, and this late too. We discussed whether I should act as his Pokémon, but I decided I will act with him, though not as part of his Pokémon team. But I will not let him come to harm if I can help it. I will protect him. I may not have been able to stop you from dying, any more than your father could. But I will protect Ash.

I'd better get to sleep. Someone has to be responsible. I hope you enjoy this letter, wherever you are, Amber.

Love,

Mewtwo.

It was early the next morning. Amethyst eyes opened, and a semi-feline face opened in a yawn. A bizarre figure drifted out of bed on a haze of psychokinetic energy, drifting to its feet lazily. It felt like there was something important that it was missing.

It left the bedroom, and made its way through the house, to find a woman and a Pokémon, a Mr Mime, preparing breakfast. The woman, who had brown hair framing a pretty face, turned to look at the figure, and smiled. "Good morning, Mewtwo."

"Good morning, Delia," the figure responded, his words (for the voice was masculine) echoing through her mind. He was tall, vaguely feline in shape, but with a certain alien nature about him. He had grey skin, with the tail and abdomen pink. The head was vaguely feline, like the body, but with harder lines that gave him an almost reptilian look. The eyes were purple and, often had a stern look to them. But they were softened in the presence of the woman who had been his guardian and caretaker for the past four years.

"Is Ash not awake yet?" Delia asked.

"Given how late he was up, watching those battles, I'm not surprised. I'd wake him, but I am in dire need of caffeine," Mewtwo responded as he filled the kettle and then put it on via telekinesis. "In any case, Professor Oak will have at least one spare Pokémon as a reserve starter, even if they're all taken. There's always that Pikachu we found eating at the wires. Though that will be at a disadvantage at the first Gym at Pewter, given that Viridian Gym is currently undergoing renovations. Then again, so would be a Charmander." Mewtwo yawned quietly.

"And…you're all right with going? I mean, considering that Team Rocket may be on the lookout for you?"

"I can't stay here forever. If they ever got a notion I am here, they would raze this place to the ground out of spite. I've been lucky so far, but luck doesn't last forever. In any case, Ash needs someone to keep him safe and sound. Arceus knows he tends to leap before he looks. And besides, it's not like I'm going to find any trace of Mew sitting around here. I may not be able to find all the answers from my progenitor, but I'd be able to find something, I hope."

"Well, you'd better be careful, okay? You may act older than Ash, but you're still a child in many ways, Mewtwo, and even with your power…"

The genetically-engineered Pokémon nodded, even as he rolled his eyes. While he believed that his adoptive mother was being overly cautious, Mewtwo also knew that there were potential limits to his power, ones he hadn't dare try to reach, for fear of attracting the attention of Team Rocket to Pallet. The few agents who had made it here, he had erased any compromising memories, even if they hadn't seen him. He was tempted to erase every memory they had and leave them drooling vegetables for the Viridian City Officer Jenny to pick up, but Team Rocket might notice that, and put two and two together. Not at all desirable, understandably. So he just erased specific memories, things that wouldn't be missed.

The kettle finished boiling, and using telekinesis, Mewtwo filled his favourite mug (with the message 'GO AWAY, I'M ALLERGIC TO STUPID' on the side(2)) with hot water, dipped the teabag in, and let it steep. As he waited for his tea to brew, Mewtwo reflected on the events that led to him coming here.

It started with Amber's death. Well, AmberTwo, but Mewtwo had come to think of her as Amber. Given the information he had ripped from Fuji's mind before he escaped, he couldn't actually blame Fuji for joining Team Rocket, at least in hindsight. It was a truism that the road to hell was paved with good intentions, and Fuji was only trying to recreate a body for the daughter he loved. However, he also was trying to create an ultimate weapon for Team Rocket, and their leader.

When Amber and the clones of Bulbasaur, Charmander and Squirtle perished, Mewtwo was left alone, feeling loss for the first time. Amber's dying gift, beyond her words, had been her memories of her life, before she became a salvaged consciousness. And when Fuji tried to sedate Mewtwo, and erase those memories, well…he was too late.

Mewtwo broke free of the tube. In a psychic assault out of sheer pain and grief, he had absorbed the memories of many of those present. He learned of his purpose, and, in his confusion and fear, escaped the laboratory. Rather spectacularly, he later learned. He wasn't sure whether he should have felt guilty for the few scientists who actually died during his escape. They weren't evil by any means, not these ones, but they had been willingly creating a weaponised Pokémon for Team Rocket.

In rage and fear and grief, Mewtwo had flown away from his birthplace, running away, not caring about the 'to' as much as the 'from'. But his fledgling powers, while still impressive, were still very much finite. He had travelled at speeds few could track, breaking the sound barrier at least once, only his psychic powers preventing himself from being torn apart by the air pressure. His powers exhausted themselves eventually, and he crashlanded in a forest not far from Pallet Town.

The next thing he knew, he was in a bed, a human boy looking down at him in concern. This was Ash, then six years old. Although wary, Mewtwo's use of psychic powers allowed him to breathe a sigh of relief. The boy he would come to view as a little brother (despite Mewtwo, effectively, being much younger) had no ulterior motives, just a desire to help. So too did Ash's mother, Delia. And Professor Oak, who had helped tend to Mewtwo while he was unconscious, was motivated by curiosity as well as altruism. These three came to be the only humans he trusted.

Through them, he learned more about the world than what he gained through Amber (who had died young) and the scientists (whose memories he had gained were, admittedly, fragmented). He learned of the complex relationships humans and Pokémon had. Indeed, Mewtwo helped Oak's research significantly by acting as an interpreter between the Pokémon and Oak. Mewtwo had, in effect, become an important assistant to Oak, though whenever other humans were around, Mewtwo used his powers to change his appearance, like a holographic disguise. It might not hold up to a particularly powerful psychic, human or Pokémon, but it would work normally.

Ash, meanwhile, had grown into a brother figure. And while he didn't actually call her a mother to her face, Mewtwo thought of Delia as a mother figure. Neither of them cared that he was a Pokémon, or engineered to be a weapon. And neither did Oak. Mewtwo didn't have much in the way of relationships, whether it be that of family or of friends, but he had those three, and that had been enough.

With the tea brewed, he took the teabag out, added milk and sugar, and then, after stirring, he began to drink. "I'm going to miss this place," Mewtwo remarked. "I'm certainly going to miss you, Delia, and Mimey. You have done so much for me, and out of the goodness of your heart."

Delia smiled at him. "Mewtwo…not everyone in the world is like Team Rocket. Sometimes, people do things for the right reasons. Have you got everything ready?"

"Almost all of it," Mewtwo said. "Including the supplies Ash undoubtedly has forgotten. Food and medical supplies for humans and Pokémon, camping equipment, spare clothes, etcetera. The only things I lack are the Pokédex, the specialised capture balls, and the analyser prototype. Professor Oak will provide those. Oh, and my tea. I'll have to make sure I stock up whenever we come to a Pokémart."

With a gesture, Mewtwo telekinetically summoned a map of Kanto, and peered at it. First, he and Ash would head north to Viridian City, before heading through the Viridian Forest to Pewter. That would be Ash's first Gym Battle, against Brock, a Gym Leader who specialised in Rock and Ground Pokémon. From there, they would head to Mount Moon, and then on to Cerulean City. The Waterflower sisters were the Gym Leaders there, though from what he had heard, the last one had apparently gone on sabbatical.

A plate with breakfast on it was placed down in front of him, and Mewtwo smiled at Delia. "Thank you, Delia."

"You're welcome. Anyway, it's the last time you'll have a home cooked meal for a while. Better make the most of it," Delia said, returning his smile.

Mewtwo chuckled. "Yeah. I'll probably have to do the actual cooking while we're camping. Ash is very well-named, given what he turns food into."

The breakfast went on, until Mewtwo realised he had forgotten to wake Ash up. He looked at the clock, and thought, Damn.

At about the same time he thought that, he heard Ash yell, "GAH! I'M LATE!"

It was a little later. Mewtwo was in his human disguise, as a tall, lanky teenager with short blonde hair, an outfit that made him look a bit like a waiter (white shirt, black bowtie, waistcoat and trousers), and tinted glasses. His expression was usually set in a mild scowl (something Gary Oak recently called a Resting Bitch Face, much to Mewtwo's irritation), and his voice, while the same, didn't have the same mental reverb, instead sounding vocal(3). He and Ash were standing in Professor Oak's lab, the latter both annoyed and tired from sprinting here and confronting Gary's little departure party. "Where in Arceus' name did Gary get a limousine and cheerleaders?" Mewtwo asked.

Oak shrugged. "My grandson is something of a prodigy, Mewtwo, but his parents indulge him rather shamefully."

"And yet, I managed to beat him rather handily in that examination," Mewtwo said with a smirk. "Something for which he hasn't forgiven me for."

Ash waved off Mewtwo's remarks. The boy with the messy mop of black hair was still in his pyjamas. "That isn't important. Professor, I need to ask, have you got any Pokémon left?"

Oak sighed. He had iron grey hair framing a stern but friendly face. "None of the standard Kanto starters. I'm sorry. The others came here early, and I hadn't expected one of them to come. I believe Gary got a Squirtle. It will be some time before I can get a hold of more. The early bird catches the worm, as the cliché goes. Or in this case, the Pokémon."

Mewtwo folded his arms. "What about the one we caught yesterday?"

A concerned Oak met Mewtwo's gaze. "Do you think Ash is ready?"

"It's better than nothing, and in any case, consider this a means of testing Ash's ability to deal with an untamed Pokémon. At least it's better than he try something like that one instead of, say, a Gyarados."

Oak pursed his lips pensively, before reluctantly nodding. "Very well." Oak then went over to a Pokéball, and released the Pokémon within.

The Pokémon was the size of a rabbit and the rough shape of a mouse, with yellow fur, dark tips to the ears, red dots on its cheeks (organs for storing and discharging electricity, Mewtwo knew), a tail like a lightning bolt, and dark eyes. It tilted its head in bemusement and curiosity. "Pikachu?"

Ash knelt down next to Pikachu. His first impulse was to hug him, but time spent with Mewtwo and Oak taught him that doing so to a wild or recently-captured Pokémon might go badly, no matter how cute it was. Plus, Mewtwo had tutored him about various Pokémon, and he knew a little about them, and getting nearly electrocuted wasn't on the agenda for today. "Hi there, Pikachu. I'm Ash."

Pikachu looked at him uncertainly, especially when he noticed Mewtwo nearby. Clearly, the electric mouse Pokémon remembered Mewtwo's Psychic move, pulling Pikachu a little roughly out from where he had been chewing on cables. Mewtwo had been somewhat less gentle than he could have been, but as Pikachu had caused a particularly vital file to become corrupted when the power shut off to his computer, Mewtwo had, understandably, been somewhat irritated.

"Anyway," Ash said, mustering up his reserves of diplomacy, "I'm going to be a Pokémon Trainer, the best that I can be, the best that ever has been. Would you like to be my partner?"

Pikachu ambled over, and sniffed at Ash. He then looked at Mewtwo, and asked, "Pika-pi?"

"I am his brother," Mewtwo responded, his psychic ability allowing him to understand the Pikachu. "As long as you don't hurt him, I won't do anything to you."

"…Chu? Pika-pika chu?" The Pikachu gestured at the Pokéball in Oak's hand.

"He's asking whether he can stay out of the Pokéball for the time being," Mewtwo said. "He doesn't seem exactly sold with the idea of going with a Trainer, especially one associated with me, but he'd prefer it to being kept in there."

"Well, sure, Pikachu! If you want, you can stay out," Ash said. He put his hand out for the electric Pokémon to shake.

A warning glare from Mewtwo cut off any possible notion that Pikachu might shock Ash, so the electric Pokémon merely shook his hand. Still, the fact that Ash had readily agreed to keep Pikachu out of the Pokéball had caused the Pokémon to at least stay with Ash for now. And it seemed that Ash was ready for his journey…well, he would be once he got dressed…

CHAPTER 1 ANNOTATIONS:

So, Mewtwo's a Ketchum, and a different meeting has occurred between Ash and Pikachu. Don't worry, Pikachu will warm to Ash…and eventually, Mewtwo.

1. Choosing Mewtwo's alias as an adopted member of the Ketchums was a bit hard. I eventually decided on Cole as a pun on 'coal', or rather, charcoal, which is, like ash, the product of a fire.

2. I actually have this mug. No, really. It's my favourite mug too.

3. Mewtwo's human appearance took some thought, but I eventually decided on a teenaged version of Shizuo Heiwajima from Durarara!