Alright, I'll do my best!
Appearance: Short, hunched, and with bad personal hygiene Lavender is a creepy looking child. He wears a dusty brown shirt and pants so holey they may as well not be there. He wears a mask identical to a Bisharp's face and walks with a limp. He has short brown hair and a scar on the back of his neck. No one knows what his face truly looks like under his mask, but it's generally accepted he only has one eye. He has blades sticking from his ribcage that elongate when in battle. His one eye is green and his hair is cut in a bowl-style. He's shorter than most.
Personality: Lavender is a mentally damaged child. He speaks softly, if he even speaks at all, and has blades that stick out from his chest. He is consistently paranoid and depressed. He is deathly terrified of heights and fire, as well as his pokespirit. He never fights himself, as his pokespirit never gives him the chance. He is, however, very smart and crafty. He can use various tools for anything he sets his mind to and, due to his silent nature, shortness, and constant paranoia, is excellent at stealth, much to Bisharp's chagrin. He does also have a soft spot for objects like stuffed animals though, as he has known them not to assault him when he speaks. He strives not for pity though and despises the thought of anyone accompanying him.
History: Born in Black City, Unova, he lived there for five years. He never knew his father, but various sources say he had died during an attack by raiders. His mother loved him though and kept him close until, when he was three at the foot of Mt. Coronet, they were attacked by wild cannibals. His mother died by their hands but in a last desperate attempt to save her son she hid him in a wrecked car, resulting in his Pokespirit being assigned, albeit without being able to speak to the child. He was later discovered by raiders, who went on dragging him along on their travels. He lost an eye during an beating caused by a group of slaves escaping being blamed on him. He was always silent to those who spoke to him, due to fear of another beating. It was 8 years later during an escape attempt at Mount Coronet, when his Pokespirit became vocal, when he learned the truth of his mother. Needless to say, he was not happy, and killed those who'd taken him in a blind fury, much to Bisharp's delight. The killing was not without it's effects however; in the assault his leg had been badly damaged by fire resulting in aforementioned limp and fear of fire, his psyche took a hard dive and he suffers from deep depression. After escaping he learned how truely alone he was now, with only his vengeful pokespirit to keep him company.
Personality: Stern and disciplined, he believes that pain is weakness leaving the body and that violence is always the correct answer. He only follows the laws because it was Arceus himself who gave it to him. He despises the child he was forced to bond with, and is VERY vocal about it. Bisharp LOVES fighting more than he does making others feel terrible.
Moves: Cut, Scary Face, Torment, Swords Dance, Guillotine, and Revenge
Other: Terrified of fire
Opening Post: A cave, a cave was the perfect place to hide himself. A perfect place to grow stronger, to train and conquer all his own. He slowly limped inside, hearing the water drip from the ceiling as he felt himself nag. "There are no fighters in here!" He heard his spirit shout at him. "We can't HIDE ourselves away! We can't let our enemies think of how INCOMPETENT WE ARE, YOU STUPID CHILD!" Bisharp continued. Lavender winced at his anger, continually wishing to himself that he would find another target to unload upon before his next battle. The caves seemed to wind on and on as they found themselves going deeper into the proverbial belly of the beast.
EDIT 1: EXPANDING CERTAIN CATEGORIES BASED ON SUGGESTION
EDIT 2: MORE OF THE SAME
EDIT 3: FINISHING TOUCHES