This sounds like fun. If I made any mistakes, it's probably because of the fact I lost all of my writing halfway through... twice. Naturally, this may sound a little rushed...

Name: Nova
Species: Pokemon - Electrike
Gender: Female
Age: Adolescent
Sect: Liberated, Tame
Personality: Careful Nature-Nova is severely distrustful, suspicious of even the seemingly most innocent things. She would pass up a group and promised safety for fending for herself, simply out of fear. It takes a lot to earn her trust, and Nova has only called one Pokemon 'friend' ever before, and that's Raikou. Nova hates being babied or the assumption that she's helpless, though she usually needs help and probably can't do much by herself, though she'd sooner rejoin the laboratory's testing group than admit it. Nova is prone to violent mood swings, bouncing from burning anger to an almost psychotic happiness within just a few moments.
Description: Nova is painfully thin, enough so that you can count her individual ribs. Her fur is patchy and falls out in clumps, barely keeping her warm in cold weather. Her red eyes, despite their infrequent use, have a constant look of mistrust and even loathing about them. Her teeth are yellow and out of use, some of them wobbling or falling out. Her tail hangs limp and dispirited, like a flag on a windless day.
History: Nova was bred with a degenerative eye disease for laboratory testing. This disease culminates in blindness and Nova can barely see anymore. Images appear blurred or don't appear at all. Nova was tested often for color vision, image perception, and even was used in toxicology studies. She was left in a barren cage in between tests with only just enough food and water to survive. Days blurred into one another, and Nova gave up all hope after witnessing the Pokemon in the adjacent cages carried off, never to be seen again. Nova and what was left of her companions were rescued by Raikou and a team of Luxray, but in her weakened state, Nova could barely run and had to be carried out on Raikou's back. She is immeasurably grateful and vowed her loyalty to the beast.

Name: Raikou
Species: Pokemon - Raikou
Gender: Male
Age: Adult
Sect: Wild Pokemon (Legendary)
Personality: Modest Nature - Raikou has a strong sense of justice and a will to defend all those in need. As such, he isn't one to be overly compassionate or sentimental and can seem cold, cynical, or even cruel. This isn't helped by the fact that Raikou despises groups that he isn't leader of. Therefore, Raikou is extremely difficult to befriend.
Raikou loathes Lugia with every fiber of his being. He believes that Lugia is to blame for the storm and resulting lightning that struck the Burned Tower. He believes that Lugia would have easily been able to calm the storm or put out the fire at the very least, but didn't out of selfishness. Thus, Raikou wholly believes that Lugia is the cause of his early death and resurrection. However, Raikou is very fond of Nova and, knowing her past, treats her as well as he can, giving her rides on his back and even acting as something like a seeing-eye dog, describing the surroundings to Nova. The two are rarely seen apart.
Description: Raikou is very proud of his coat-arching stripes; elegant, billowing storm clouds... he believes he is the most good-looking of all the legendaries and will devote many minutes a day to taking care of his precious coat. The resulting shine is almost blinding and makes Raikou look as though he is made of pure gold.
History: 150 years ago, lightning struck the western Bell Tower in Ecruteak city, resulting in a fire that burned for three days. The fire was put out by a sudden rain, but the tower had already burned to the ground. Three nameless Pokemon perished in the fire. Ho-oh, pitying the Pokemon, resurrected them with his divine power, striking fear and awe into the hearts of all those who saw them rise. The Pokemon, knowing their power, fled into the grasslands, rarely ever seen by human eyes ever again.
Raikou, having rarely seen the other Beasts, has assumed they are dead and decided to take over their responsibilities, though unsuccessfully.