Hisa appears as a very attractive pale young woman, with long dark hair she keeps pinned up. She typically dresses very elegantly. She has two expressions, a sort of detatched boredom and outright fury. She does not speak. Unless she makes an effort to hide them, her eyes are solid shiny black.
She gasped, trying not to choke on the blood in her throat. Her vision was blurred, and she could only see shadows and shapes. Her fingers were bloody from clawing at the ground, trying to drag herself along. The pain had receded to a dull annoyance. All she felt now was the rage. He’d pay, the one who had done this to her.
Hisa was a girl from a small village. She had everything, beauty, pleasing talents, and a wealthy and aging father who doted on her. She naturally had many suitors, but she did not like very many of them. One in particular did not take no for an answer, despite being sent away several times. When it was announced that she would marry the son of one of her father’s friends, this man decided to take what had been denyed to him. He abducted Hisa, raped her, and then brutally murdered her.
Two shadows moved toward her, but she could not make them out. Low voices drifted to her. She tried to cry out, but that man had taken her voice and all that came out was a low gurgle.
"She won’t last long. Even if she was found now."
"Mmm, she has fire. She won’t lie quietly."
Hisa’s death was so violent and her rage was so great that it was impossible that she would simply pass on. Her spirit lingered where she had been killed, nearly berserk with fury, even after the death of her murderer. For almost two years, the area she haunted was considered a deadly place. Then something changed.
"Well, she’s calmer, now. I suppose she woke up."
An indistinct shadow approached her, and someone gently lifted her face. "She understands pain, and the hate there is appealing… but no. Too much rage, no appreciation for the beauty of suffering. She’s of no use to me."
Another shadow approached and repeated the process. "The right or wrong doesn’t matter to you, does it? No. You want to punish everyone now, not just the guilty. I can’t help you." The shadows melted away, leaving her to do as she liked.
Hisa was not a normal ghost. Her fury and lust for revenge were enormous, greater even than that what kept normal ghosts from the afterlife. Her feelings were so strong that they took on a life of their own, bound together by the last vestiges of her personality. Hisa’s ghost became a demon that fed on revenge.
No longer bound to her place of death, she wandered. She was drawn to those who desired revenge, and fell into a pattern of helping such people. It didn’t matter who they were, who they wanted revenge on, or what the greviance was. She helped a knight track down and destroy an evil wizard, and she helped a murderous overlord destroy the hero who had ruined his schemes. It was all the same to her.
Hisa does not have any overtly "magical" abilities; her focus is more physical. She is much, much stronger than she looks like she has any right to be, and a good deal faster than normal humans. She is also remarkably resilient and hard to injure. It is possible to "kill" her, but it is only temporary and just makes her very angry. It may take a long time, but she will be back eventually.
Hisa has a particular knack for locating her or her companion’s prey, a gift that those she associates with often find invaluable. She also has a rudimentary instinct for finding people’s weak points (psychological, physical, whatever), although she usually lets her current companion worry about finding something exploitable. She will always let her companion decide how to handle pursuing their revenge.
Hisa is usually very calm and acts in a calculated manner. However, it is possible to make her mad, and then she is prone to violent rages. She will do whatever her current associate wants her to do as long as it’s in pursuit of revenge (seduction, bait, violence, whatever).
She is completely mute and normally shows no expression at all. Since she can’t speak to give her name, she allows her companions to call her whatever they wish.
There are some downsides to attracting Hisa’s attention. A vengeful obsession strong enough for her to notice is a fundamentally self-destructive behavior, and her presence just makes it worse. Her unquestioning help and abilities often tend to fuel god complexes (which the people she associates with are already prone to). And once her current companion has satisfied their revenge, she’ll move on… possibly helping the very people her former companion went after. That’s not even taking into account any possible ramifications for dealing with demons in general.
Hisa usually chooses her own masters, but she is a demon, and she can be summoned. It would probably be a *profoundly* bad idea, of course.
Currently, Hisa’s companion is Dr. Emil Vincent, a homicidal madman. His obsessive drive for revenge is what originally attracted her, but his manner towards her reminds her (vaguely) of her father, and she’s developed a sort of affection for him. He calls her Etellia (he simply liked the sound of it), and she functions as a servant and companion, in addition to assisting with his schemes for revenge.