Cortana Starling

 Cortana Starling (コルタナスターリング Korutana Sutāringu)

Appearance
Cortana is of average height and weight for a woman her age, with a large bust and curvaceous hips. Physically, Cortana is in good health: She has a healthy and athletic body, unscathed skin apart from a few scars, full, coloured lips and silky hair. However, she seems to possess naturally white bangs she has had since she was barely able to walk. She also possesses dark magenta eyes, the pupils of which slit when angered. It should also be noted that when her Opposing Worlds magic is activated, her eyes turn into the Yin-Yang symbol.

Cortana is usually seen donning a dark green, skin-tight bodysuit with a relatively tattered camo green cape. The material of this outfit is sewn with thread laced with very small Lacrimi, providing extra resistance to wear and tear, as well as volatile magic such as Natsu Dragneel's Fire Dragon Slayer Magic. The bodysuit also has a white stripe straight down the middle of her chest, and around her waist, similar to her knee-high boots, which also have two white rings on the middle and the top rim. She also wears a pair of black gloves made from leather.

Personality
To be done.

History
To be done.

Magic and Natural Abilities
Opposing Worlds: Opposing Worlds (世界に反対, Sekai Ni Hantai) is a peculiar, rare, Caster Magic. It is a highly prized magic that is difficult to learn, and hard to maintain. In order to utilize Opposing Worlds, one must select a certain, so to speak, "world" to focus on; night, or day. This type of magic revolves around the use of magic commonly associated with night and day; one being for purifying and healing, while the other is commonly stereotyped into darkness and danger. The magic is extremely dangerous, as it can tear the user apart if utilized incorrectly. Although not impossible, it is extremely difficult to achieve the use of both the day and night versions of Opposing Worlds. Rui has been able to achieve this feat, however she prefers the night version as opposed to the day version, but in order to fully master the magic, she took the time and difficulties to learn both versions. Technically, it is not considered Lost Magic, but is considered to be on the caliber of it; as it is incredibly rare, and powerful if used correctly. As the name suggests, night and day are two "opposing worlds"; each are most powerful at the respective "worlds". The day version relies purely on sunlight, and barely any Eternano, thus making it useless at night. The same is for the night version. However, the night version is slightly altered. Since moonlight is just the sunlight reflected by the moon, the night version is slightly stronger than the day version, but not by much.

Familiar Spirit Magic (使い魔の精霊魔法, Tsukaima no Seirei Mahō): This magic is used by creating a contract with a spirit. The spirit can then either be manifested into a physical form, fused with the user or fused into an item. The magic that a Familiar Spirit uses is different for each spirit, some can use Fire Magic, Water Magic, Wind Magic etc. Making a contract with a spirit can be very dangerous, if the spirit feels that the mage is too weak to be its master the spirit can eat and/or destroy the mage, or the spirit could just leave. The results of a failed attempt at this magic really depends on the spirit the mage is trying to make a contract with. When a Contract is successfully made a stigma is left somewhere on the mage's body to symbolize the Contract (the power of the contract has nothing to do with the location of the stigma). The Contract is valid until the mage dies, for whatever reason, and the Familiar Spirit is then released until another mage manages to form a Contract with it.

Telepathy (念話, Terepashī): With this Magic, the user is able to talk to other people through their thoughts and converse over long distances. A strong Mage like Cortana herself can use this Magic with a mass of people.

Immense Strength: Cortana possesses inhuman strength virtually on par with the likes of Natsu Dragneel and Gajeel Redfox. She has been seen shattering entire stone walls with a kick and making craters with missed punches.

Master Hand-To-Hand Combatant

Master Swordfighter

Trivia

 * Cortana's appearance is based on the X-Men character Rogue, all credit goes to the creators of said character.