Partner Pokemon: Mewtwo and Ralts.
Reason for joining: Psychic-Types have very good Move-Pools and capabilities that many Types don't have. They are perhaps one of the best Types around, and considering that it had only one Weakness (Bug, which is weak anyway), it was practically the best Type in Generation I. There were only three Bug-Type moves to counter Psychic then, all of which were very weak. That is one of the reasons why Mewtwo was such a threat back in Generation I.
Favourite Psychic-Type Move: Psychic (See what I did there?). 'Nuff said.
What is your favourite Psychic type pokemon?
I'm going all the way back to the First Generation and say Mewtwo. Back when I first saw it, I knew I should catch it. Mewtwo had like, the best back-story ever, and was such an awesome Pokemon I decided to get Pokemon Yellow to get it from Cerulean Cave and transfer it to my first Pokemon Game, Pokemon Gold (When I found out that Mewtwo wasn't available in that game). After that, it took quite a while to get to the one place I needed to go to for this awesome Legendary; Cerulean Cave, the big Cave which had the most powerful wild Pokemon in the game. It still took a few minutes getting to the destination, but when I had finally got to the final part of the Cave, there it stood. Mewtwo. I knew that it was Level 70, and that it was going to put up a big fight, but my Pokemon was good enough. So I had my Pokemon battle Mewtwo, got it on low health (With the help of the Sleep Condition so it couldn't use Recover), and when it was just about on it's last HP point, I used a Poke Ball (I didn't want a Master Ball, I would rather catch Legendaries in Poke Balls). Wobbled 1 time, then popped open again. Then Mewtwo woke up and started Attacking again. When I had only one Poke Ball left, I knew this would only work by luck. I threw the last of my Poke Balls, it clicked, which meant I caught it. I quickly got to the Transfer thing and transferred my Mewtwo to Gold Version, and now it is my favourite Psychic Type. But it's still not the best Pokemon...