Hmmm, I definitely have a Mon for you, KS. Editing as we speak. ^_^
KS, take Anger the Magikarp. Now, this Magikarp is pissed off at the world, and for good reason, since everyone makes fun of its' species in general for being 'weak' and 'pathetic', along with a few other reasons. Since I'm not a mean person, there are no restrictions whatsoever until you evolve it. Then the fun begins. Originally, Anger was a happy, surprisingly intelligent Magikarp that lived on an offshore cave with its' parents. But one day, someone by the name of Cyrus came to this cave and attacked Anger's parents. Despite Anger's best efforts, its' mother was killed by Cyrus' Honchkrow, and its' father was caught by Cyrus. Seeing Anger as a useless Pokémon, Cyrus orders his Honchkrow to kill it, but it miraculously survives the attempt. Soon afterwards, you catch the Magikarp, and notice it has a very belligerent attitude, attacking anything that it saw to attempt to cope. It must participate in at least one major battle before evolving, although it doesn't have to attack. Once it evolves, its' rage amplifies, and now it has the means to enact its' revenge on Cyrus for what he has done. First off, because of its' trauma, it can not use moves above 100BP, and when sent out into a battle, it goes into a violent rage, and will only listen to the first command you give it before going wild. Randomly pick a move each turn to imitate disobedience.
Because of the severe trauma that Cyrus put on Anger with the death of his mother and capture of his father, Anger must take out at least one of Cyrus' Pokémon in the Ruins and Headquarters, and he must solo Cyrus in the Distortion World. Have fun. :O