Lady Merci

Lady Merci is the current alias of an immortal cat burglar formerly belonging to an ancient clan of ninja who she betrayed after their master performed cruel experiments on them in the pursuit of power, leading the other survivors to pursue her out of vengeance well into the modern day.

Appearance
Merci is an albino rat standing at around 5'4, with a slim, toned hourglass build. Her fur is primarily pure white with pink vine-like markings across her body and coiffed hair in a matching hue. Neither are dyed or painted, instead being permanent markings that persist even if the fur is lost or hair is cut.

She frequently wears makeup, including eyeshadow, lipstick, and specialized nail polish that serves to strengthen her claws. On her left ear are two stud piercings bearing her initials, L and M.

Her 'work' attire is composed of utilitarian zipped catsuits in dark blues and purples, frequently accented with ninja-like wrappings around her wrists and ankles, hinting at her past. Her 'casual' clothing follows a similar vein, favoring loose and nonrestrictive garments in dark colors.

Personality
Boastful and self-assured with a snide, flippant sense of humor backed up by multiple lifetimes worth of experience and sharply-honed skill. Generally introverted, she immensely dislikes being forced into the open or confined, growing anxious if placed in situations with no clear way out, though she is quite adept at creating escape routes in a pinch.

When relaxed, she may come off as flirtatious, lazy, or absentminded but is in actuality almost always analyzing her surroundings and the body language of anyone nearby, searching for openings to exploit if the situation calls for it, making her a resourceful ally and formidable adversary. However, this analytical nature may be detrimental when safe and around those she trusts, taking some effort on her part to reign in.

Abilities
Merci is an adept thief with unparalleled skill in the arts of evasion, stealth and acrobatics—and near-mastery of several disciplines of combat martial arts—all acquired from her ninja training and the 500+ years of lived experience that followed. She, along with her surviving former clanmates, also possesses supernatural talents granted by a dark arcane procedure in her youth, including enhanced strength, senses, and regenerative ability at least strong enough to effectively halt the aging process, making her immortal.

Her other abilities aren't as well documented, but are rumored to include the power to seemingly vanish into the shadows, as well as a sort of radar-like situational awareness bordering on ESP.

Grappledart
Merci's primary tool and weapon is a mechanical three-pronged grappling hook that can fold up for use as a rope dart. She is lethally proficient with it, able to guide its trajectory with pinpoint precision and bone-shattering force. Far from being solely a weapon, however, its grapple configuration allows her to traverse great heights and swing through the air as if in flight, when coupled with her acrobatic ability.

Hasu Clan
Merci, birth name unknown, spent her early years in Nihoto as an orphan until being conscripted into the Hasu Clan, a secretive group of ninja. Under the name of Nezumi, she was trained in the ninja arts before being sent on numerous dangerous missions of assassination and espionage.

Soon after this, however, their Master sought greater power and began to dabble in the arcane, performing cruel experiments on Nezumi and her clanmates, giving them their powers and distinctive markings, but ultimately triggering Nezumi's betrayal—his murder. After the following brief fight and pursuit, Nezumi throws herself from a great height and is gravely injured from the fall, barely saved by her regenerative ability. Assumed dead by her clanmates, her body is thrown in a river but washes up near a fishing village where she's nursed back to health and soon flees the country, while her clan is none the wiser.

1500s-1900s
Much of this period is spent traveling the world and honing her skills as a thief. A significant portion was spent in Marrenia, where she picked up her characteristic accent.

70s
At some point in the early 70s, her clanmates learned of her survival and hired bounty hunters to track her down, including the legendary Kai, leading to a violent series of fights and Kai's eventual (apparent) death.