To all those people who say Light=Psychic, think before posting.
The only Psychic Pokémon who I would consider "Light" would be Espeon. And that is only because it is the opposite of Umbreon.
There are more evil Psychic Pokémon then good Psychic Pokémon:
1. Mewtwo. It destroyed a whole science lab on his own and probably killed many humans while doing it. But although that, I don't really think that Mewtwo is evil.
It was experimented on untill he became horifically mutated and psycological scarred until the day it had enough and wanted to escape. Then it escaped deep into a hidden cave to avoid all contact with humans. How evil.
And it's pink. How can pink be evil?
Anyway, I wouldn't call it "Light" in any way.
2. Lugia. As Ho-oh represents the sun and the day, Lugia represents the moon and night. And as we all know, the night is evil while the day is good.
3. Deoxys. I also don't consider this one evil as well, because it is just like Mewtwo. It didn't do anything evil and it fled away from all humans.
4. Alakazam. Finally the real evil Psychic Pokémon. This one had many rebels against it, because it looks like it worships Satan. That can't be "Light".
5. Drowzee/Hypno. They eat by putting it's prey to sleep and then eating it's dream and gives you nightmares in return. It's also listed in the Pokédex that a Hypno once took away a human girl whom he hypnotized.
6. Giraffarig. Giraffarig itself isn't evil, but it's tail is.
7. Wobbuffet. Just look at it's tail. Just like Giraffarig, it's tail is evil. And also look at it's ability: Shadow Tag. How can prefenting the opponent to escape using it's shadow be considered light?
Psychic Pokémon are far from Light. Most Psychic Pokémon are just animals and as we all know, animals aren't good or evil.
And just look at the attacks. How can you asume that using your mind as weapon is the same as using light as a weapon? Anoth great example here is Hypnosis. Hypnosis puts the enemy to sleep. I don't know if you've ever tried to sleep during the day, but it's much easier when it's night and dark. And sleeping also isn't light, as in good. Sleep and death are often assosiated with eachother. In the Greek mythology, Hypnos (Sleep) and Thanatos (Death) are eachother's brothers. They thought that Sleep was just a temporary form of Death.
That is also partly why I think there should be a real Light type.