Before this modern, industrial age of steel, before darkness descended upon Kanto, in an era when the power of shadows was a mysterious one which scientists struggled to study (and their ghost-type sources believed to be little more than local myths) psychics ruled the land. A myriad of types had been replaced by an omnipotent few, and beasts like Alakazam, Starmie, and even Hypno seemed invincible – or they would have, if not for one electric-type pokemon.
It is not that Pin Missile is a super effective attack, or an especially powerful one. Indeed, other pokemon can use an attack identical in name, if not in form. But while a Beedrill fires a few barbs from its stingers, a Jolteon's fur is composed of ten thousand thundercharged needles, which can be fired in a devastating barrage in any direction from any point on its body. In terms of physical damage caused, it is actually much weaker than a thunderbolt, but few pokemon realize this, for it hurts far, far more.
The objective of a Jolteon's Pin Missile, after all, is not injury but pain. Jolteon are sadistic creatures, seldom in a good mood and always willing to cause suffering for the sake of schadenfreude. And although most pokemon run on adrenaline until the battle ends, and a few turn their wounds into a source of power, psychic-types lose their concentration and soon wake up full of painkillers in a pokemon center.
Today, Jolteon are feared more for their speed and thunderbolt than their needles. But although it was Magneton and Gengar and the inventors of the Shadow Ball technical machine which finally ended the age of psychics, let it never be forgotten that it was a Jolteon who prevented Sabrina from becoming Champion and turning Kanto into a psychic dystopia.