Enfor

Mewtwo. A legendary pokemon created not by evolution, but by genetic tampering. It represents, perhaps, the pinnacle of modern science and genetic manipulation, of mankind improving upon nature itself.

You don't get that kind of success without a lot of failures along the way, and subject N4-(Sometimes called 'Enny' by a more whimsical researcher), a fusion of mew and human DNA, might seem to be one of them.

But looks are decieving, and calling him a 'failure' is unfair. He was, in reality, a rousing success. In order to genetically alter something the way you want, you often need to find the genes that control what you're interested in. And the easiest way to do that is what are called 'genetic knockouts': test subjects who've had a specific gene altered so as to be inactive. You can look at what happens to the organism as it develops, and get a rough estimate for what the gene you deactivated did. And with subject N4, they found one of the gene's they'd been looking for. One of the genes they'd need to modify to make Mewtwo a reality.

Sometimes, the researchers called him a "Mew-Zero". Because subject N4 has almost no psychic abilities whatsoever.

This is not to say subject N4 has no psychic potential, or no psionics at all. Biology is rarely so simple--the gene, further research suggested, had more to do with access and control of psychic powers than with psychic ability in general. Indeed, N4 actually probably has as much psychic power inside him as a sub-average mew, but N4 has no ability to harness it. He can't fly. He can't move things with his mind, or generate psychic blasts or barrier-bubbles. Even learning to 'talk' using his psychic powers took an inordinate ammount of time and effort for something that should come almost as natural as breathing.

And there are other side-effects. N4, like many mews, can passively feel the emotions of those around them. Unlike most mews, N4 can't shut it off. Unable to regulate his own psionic abilities, N4 is constantly subjected to small doses of the emotions and sensations of those surrounding him (provided, of course, it's not being blocked in some fashion). It's caused him to develop an eager-to-please personality, and a strong aversion to making folks angry, upset, or disappointed. At times, even sensations can filter across the link, something that can be deeply disorienting, but he's gotten better and handling such things.

Eventually, of course, the facility he was housed in was destroyed during Mewtwo's escape, and during that, N4 also escaped into the wilds....