Mostly focused on giving her powers similar to the lighthouse poltergeist in the show. I'll start working on a sketch now, I hope to have a colored drawing ready in the near future.

[hider=Melanite CS][b]Name:[/b] Melanite

[b]Appearance:[/b] Melanite is between Amethyst and Pearl's heights, and mostly black or dark gray in appearance. She has a short poof of curly hair, and frayed robes that make her look like a ghost.

[b]Gender:[/b] Female

[b]Personality:[/b]
Melanite has a mischievous streak, often using her powers to play pranks, but she means this always in good fun, and is part of her habit of constantly misunderstanding what makes people happy. Melanite has a constant drive to bring cheer and fight evil, which drove her to fight against the Homeworld when Rose Quartz's rebellion began. However she has a hard time figuring out how to please different people specifically, so she often attempts to help people or express her joy through pranks or tricks. Melanite's insufferably light-hearted demeanour often makes it surprising for people to learn she loves gory horror and action movies.

[b]Bio:[/b]
The Melanite species of gem were used to help operate simple machinery through possession, but as gem technology began to advance and harness magic to function, these powers began to grow obsolete. At the tail end of her usefulness to homeworld, Melanite took part in creating Kindergartens on Earth, destroying wildlife to create more gems. Melanite couldn't justify the actions of the gems when she saw the destruction firsthand, and she fled the homeworld gems and hid away, a task made easier with her powers. For a long time Melanite could only feel anguish and remorse for her own deeds, until word reached her that a rebellion had been started by Rose Quartz that sought to defend the Earth, and it gave her a cause to channel her remorse into.
During the war, Melanite's kind personality was consumed by her passion for fending off evil, and when her gem corrupted she became a selfish spirit that lashed out against all who hurt her. As a formless spirit surrounding a singular gem, Melanite was passed around by humans who mistook her for a valuable stone, bringing misfortune to humans who owned her, until she eventually became buried in the lighthouse in Beach City.

[b]Association:[/b] Melanite was loyal to Rose Quartz at the start of the rebellion, and still is.

[b]Gem:[/b] Melanite

[b]Weapon:[/b] None

[b]Gem Location:[/b] The back of her head.

[b]Gem Unique Ability:[/b]
Melanite has the ability to possesses non-magical objects, which excludes living beings as well. Melanite phases into an object, and her gem relocates to a location inside the object she possesses, a location she chooses but can't change once she's in control. This object can be as large as a building, and if so she can use telekinesis to move anything non-magical that isn't too strongly secured. If she possesses a machine, then someone controlling the machine could possibly restrict her movements. She can move the thing she's possessing, but a building is attached to the ground too strongly by its foundation for her to move it. A car would be no problem, though. Damaging the object she's possessing hurts her, and destroying it completely forces her to retreat into her gem.
Melanite is physically weaker than most gems (but probably still stronger than humans) but she can levitate. Melanite cannot easily shapeshift into anything non-humanoid or shapeshift parts of her body selectively, but she can create projections like Pearl can, and often does so to share memories.[/hider]