Blinkly the gnome, his mind made twisted and corrupt by Lucint, began working on an evil device. Through Lucint’s instruction and influence many plans were drawn up. Plans so foul many men would not dare speak them aloud. The two captured several towns’ worth of innocent villagers and took all their supplies with them. After many months of work, the demonic device was complete.
When it was finished the machine was the size of a small manor. Many flasks lined its outside filled with putrid liquids found only in the deepest reaches of the abyss. These flasks were connected to the top of the machine with tubes made of human skin. At the bottom of the device there are two openings. One on the bottom left and one on the bottom right. Any creature, living or dead, that is inserted into the left opening will be stripped of its skin, then flesh. What remains is sent to a furnace which burns the refuse for energy. Any living creature that is inserted into the opening on the right will, depending on its views, either receives a blessing or a curse worse than death.
In order to make the device function properly, all of its outer flasks must be filled with an abyssal acid. The left opening must be fed at least one large demon and three adult humans. Then, a person must go into the opening on the right.
When the device is functioning properly, anyone who has entered the right side opening will be stripped of all their belongings. The machine will then proceed to pour it’s flasks of acid onto the person. This will, naturally, cause a substantial amount of damage. The device then goes into a horrid process in which the flesh of a demon and the skin of the humans are melted onto the person inside. This should also cause quite a bit of damage.
When the person leaves he has, in essence, become a demon. He should gain their strengths as well as weaknesses. He should appear to be little more than a large and deformed human to most. And his movements may be awkward and sluggish for a few days after this operation.
The "wearer" may also gain a form of natural attack. Such as a claw or large teeth. Perhaps the ability to secrete acid through his pours.
The downside comes with the fact that dead flesh rots. This graft will last no more than three days unless it is treated with some sort of preservative. This could be achieved through a spell. Though another dose of the abyssal acid will work to sustain it for another week.
Should the graft rot off the former "wearer" is simply brought back to his old self. Though if a penalty is to be imposed then his movements may be become awkward again. He may be tainted from living as a demon. Or he may have received permanent scarring from the acids.