I'm working through some personal phobias with this character and its background. Apologies if its a little much.
Name: Jon Addaam, sometimes goes by his demon's name, Kad'nezir
Class: Unwilling Warlock
Languages: Demonic, Extremely crude Orcish, Common, decent Gutterspeak, about eight words each of Darnassian and Dwarven.
Faction: None, but seeking association...
When not posessed by his demon, he is startlingly upbeat for what he looks like; often cracking jokes and being friendly with any nearby associates. However, on occasion the constant agony of his wounds can overwhelm his usual self, causing him to lash out in rage at anyone nearby, including himself. Seems extremely jealous of the dead.
When posessed, the demon pretends it can only speak Demonic, but gives itself away with very little prodding. The demon is spiteful and hateful and will insult anyone working with its "master," especially any underlings of his nearby. It may or may not work towards the same ends as its master.
Likes: Drinking himself slowly into a forgetful stupor between campaigns. Destroying things that deserve destruction, with a very loose definition of "deserving."
Dislikes: His demon and the pact it has forced on him. Kittens, especially the fluffy ones. Small children, but the feeling is mutual there.
Appearance: Dark blue eye, missing the right one. Startlingly pale skin. Absolutely no hair on his head. Teeth only on the left side of his mouth. Missing his entire left arm and right leg below the knee. Has a serviceable pegleg that is easily detachable. When his demon has been summoned, it is merged with him. His left arm is much more heavily muscled than it should be, a dark purple in color, and ends in long talons. His right eye is a glowing demonic green. He has demonic fangs on the right side. The leg grows out of the stump, knocking off the peg, and is obviously demonic in form with a cloven hoof. Both arm and leg are a bright purple that glows, but so faintly that it can't be seen except in utter darkness. He also sprouts faintly glowing purple hair that is about 2 inches long and a foot long curved horn over his left eye. Wears purple robes that look heavier than their cloth should be, covered in black runes, with certain runes of high power in stark white. Wears no shoe, but the foot (and the rest of him as well, if anyone got close enough to touch) is unnaturally warm. Has a black staff with the appearance of the bones of a left arm, the palm flat and down, and 6 feet tall, with an eye on top of the other end, where the arm would attach to the shoulder, that appears to move about on its own. This is actually what is left of his own left arm and right eye, and he uses it as a crutch. In combat, while he is infused with his demon and its bodily replacements, this staff can move on its own, grabbing things in range, and slowly casting spells that do not require speech.
Strengths: Knows people both in the Alliance and the Horde. His magic is fairly potent, when it works at all. Being almost half demon grants some of their properties while he is in that form: greater hearing and eyesight, attunement to magical emanations, greater strength. Sharing a body and mind with the demon means they work better together than most other beings, virtually symbiotically; they can cast spells independently of each other if they focus hard enough. They learned long ago not to argue about who controls what during combat, since if one dies the other dies as well. Each communicates with the other as if thinking to themselves.
Weaknesses: While the demon has been dismissed, he is obviously crippled. He is near madness most of the time. The demon will fight him for control whenever it can safely do so. He often cannot dismiss the demon on his own; it must usually be banished by an outside force.
History: Still not done here, but this is most of the important part.
Jon's imp pulled itself up until it could see what was on top of the table. "You know this cannot end well, Master."
He backhanded the imp so hard it crashed into the wall underneath another table, this one with an elaborate alchemical apparatus on it, dripping a dark green liquid into a flask. "Either help or begone, Tlaskeen."
The imp staggered to its feet and shook its head to clear it, then flapped about getting various knives and pans situated as his master directed. Jon then began the examination and dissection of what was on the large table in the middle of the room: a well-secured Nathrezim demon, each limb strapped down above and below each joint, three straps across the torso, one along the neck, one across the chin, another the forehead. The last two straps were tied to its horns. The binding spells and potent drugs each ensured it could not move, but Jon was taking no chances with a demon this powerful soon to be in excruciating agony.
First, Jon took a specially made and sharpened spoon, and removed one of the demon's eyes. He muttered to himself as he took it apart layer by layer, making notes and drawings as he did so. After finishing with the eye, placing what was left of it in a jar of preservative, Jon grabbed his special flenser and headed to the demon's side.
The demon glared at him and growled, twitching the muscles, as Jon carefully removed the skin on its lower right arm, documenting its thickness and consistency. He then made detailed sketches of the muscles underneath as they oozed the demon's equivalent of blood and strained against magic and potion and bonds. Jon then removed muscle and tendons, down to bone, taking many, many notes, while the demon gurgled what would have been a scream of rage and pain, if it had full use of its mouth and vocal cords. After several hours, the entire arm from shoulder to fingers had been examined in this fashion. Any mortal creature would have long since died from the amount of blood lost by the Nathrezim. Jon had simply to pull, and the bone came out of the shoulder. He placed it with the others. The imp had fled in terror, noticing that the much more powerful demon was nearly through the binding spell, and the potion had long since worn off.
Jon calmly walked to the head of the table to dose the demon with more of his paralytic potion. As he went to dump it in the open mouth, the Nathrezim's remaining arm snapped all its restraints and grabbed Jon by his shoulder, claws piercing all the way through. Jon's scream of pain was drowned out by the demon's bellow of anger as it flipped him onto itself.
"You wish to know more of the Nathrezim, human? Here are some lessons. We can ignore pain if we need to. We are virtually immortal. Our strength is far beyond what your body can endure." At this point the demon sharply jerked its arm to the side, virtually duplicating the surgical maneuver Jon had been doing to it, but on the opposite arm. "And our legs are even stronger." The enraged demon's legs snapped their bonds as if they didn't exist, and it clapped its feet together, their sharp edges shearing through one of Jon's legs. He was barely conscious at this point, eyes rolling in agony.
The demon snapped the rest of the straps, stood up, and slammed Jon down where it had been. "And we are vengeful beyond your comprehension." The demon then slowly gouged out one of Jon's eyes with a claw. The Nathrezim continued to burrow the claw deeper as Jon started laughing, a wild cackling that spoke of insanity. The contingency spell he had placed took effect when the demon actually tried to kill him, blowing it apart. the remains of its head landed over Jon's like a mask.
"As I said, we are nearly immortal, human. And we have a thirst for revenge." The demon's mind coalesced into Jon's, its whole body parts replaced his own missing ones, searing themselves on. Jon could smell roasting meat, his own flesh, through the demon's control. Suddenly, Jon had full control of himself again.
"And you think I only had one spell prepared for your release? Now you are bound again, inside my mind." Jon closed his eye. The one imparted by the demon stayed open, however, until he concentrated on it.
The Nathrezim screamed at him in his head while he slowly learned to control its replacement body parts. After an hour or so, he opened his eyes and felt confident enough to stand up. The demon's leg was slightly longer than his own, and it took him another few minutes to figure out how to walk properly with it. He glanced around and saw that his laboratory was completely destroyed. His arm was charred bones somehow held together by tendons and scraps of muscle. His eye had landed in the flask of green liquid. It seemed to stare at him accusingly.