Mikuru Asahina

Your body can expel freezing winds that, depending on the exit point, have a chance to freeze the enemy. On top of that, shards of ice are generated at the exit points as well. The amount, sharpness, and thickness of them depend on the exit point as well.
*Using your hand, the chance to freeze is low, but the hand produces the most ice shards (20). These shards are moderately thick but they are are dangerously sharp though, capable of effortlessly piercing skin and muscle. It can also pierce bones as well. The shards can sink about 3/4 of their 12 inches into a person. Only half of the shard will sink into a bone.
*Using your fingertips, the chance to freeze is moderate. Finger tips only produce about 11-15 ice shards. Using one finger, produces eleven, and you gain one more shard for each finger added. The shards can pierce skin and muscle. But only the first 3 inches will go into a bone. Half of it will sink into skin and muscle. The ice shards are fairly thick but are still quite sharp.
*Using your mouth will produce the highest possible chance to freeze an enemy. Using your mouth will produce about a 90% chance to freeze the enemy (not factoring and environment conditions or their bodily condition). However, this method only produces 5 shards of ice. Ironically enough, these are the sharpest shards giving them the highest chance to dig deep into skin and muscle. About 10 of the 12 inches will sink in. Piercing bone is possible, but even with the sharpness of the ice it will only sink in about 4 or 5 inches. The ice isn't incredibly thick either. But despite this, it just makes them move the fastest.
Note: The odds of freezing depends on the ENEMY'S body condition. The weaker they are, the more at risk they are of freezing. If the enemy is weaker than the caster, then they are at a higher risk as well. If they are stronger than the caster, the risk goes down.

LIFE
Mikuru was born into a middle class family of merchants. She was the youngest daughter of two and due to deb, her mother sent Mikuru to a Geisha house, where she would be better taken care of by a friend of the family and safe from her abusive uncle and drunken father. Over the yreas as Mikuru grew up she became very beautiful and talented in many arts. Thankfully Mikuru's “mother” thought it best for her girls to be skilled in martial arts, so they could defend themselves and be more graceful in balance. In her first coming out as a Geisha Mikuru was chosen to be the performer for a very high society party and was payed extra to be the attendant/ female company for the party host. A few years later, Mikuru was 18 and she was thrown a party by a lord and his son, whom had known Mikuru since her debut. The celebration was a blast and later that evening Lee took her to his private room to exchange presents in peace. As the night went on they ended up having hot and dirty sex. But once that was over Mikuru began to feel lighthead and sick.
....Poison?...but who?....Looking over at her lover,Lee was leaning over her with a grin. “I' sorry my love but , I covered my lips in poison so I would be your only love and your lovely eyes would only look upon me. Hence the posion, now sleep well and just let it overtake you. It will be less painful that way. Then I will one day join you in the after life.” He leaned down and kissed her cheek one last time. Mikuru looked at her love with hate for killing her, sadness, and pity for now he would be alone and as would she. “you bastard, die in hell and I curse you to live alone and die a painful death.” Those were the last words she spoke while alive and in her once lovers arms.

ARRANCAR EVOLUTION
when Mikuru awoke next she was in a distant place and had a body that of a hollow. It didn't take her long to figure out she must eat souls to stay alive. She got tred of just catching random humans that had nothing to deal with her and went to kill those from her past seeking revenge. So she killed lee, her abusive uncle, and those that hurt her or those people that she had once loved. This revenge is what fulled her to keep alive and become stronger. As time went on she found human souls were no longer satisfying to her, so the next time she ate she ate another hollow. She continued to do this till one day she turned into an Adjuchas. Then she found in order to keep her mind hers, she had to eat more hollows ad more hollows. This battle was hard, each day having to eat more and more hollows just to keep her mind hers and not to be eaten herself. The battles were fun and entertained her if nothing else, this place was boring except for fighting hollows that were weaker then her.Eating all these hollows increased her power and made her thirst for more of the succulent and deletable flavor. So she continued to hunt and fight each day to survive, even though it was lonely, she continued to gain the power and used her rage from revenge to keep going.A few years later, she had wondered far into the into Las Noches she was turned into arrancar, after though of proving she was strong enough to handle and ruthless if need be to be arrancar.