Ruya Shiraino - Leader of the Shiraino clan, half Yukikaze,

Name: Shiraino

Origins: Near the mountains of the Yukikaze Clan's base. Ino of the Boar and Shira of the ice. This clan originates from the forests surrounding the Yukikaze mountain.
Like the Senju and Uzumaki, the Shiraino clan and the Yukikaze clan were life-long partners. Often, sending a few maidens to marry off the Yukikaze shinobi. Ruya's mother, Kojinko Yukikaze married the leader of the Shiraino clan, Hafuu Shiraino.

Founder(s:( Oroki Shiraino and his wife, Pienna Shiraino
Leader(s:( Ruya Shiraino
Symbol: http://www.julietemckenna.com/wp-content/gallery/runes/323_air.gif
Village:

Kekei Genkai
Name of Kekkei Genkai: Lightning Winds

Abilities of Kekkei Genkai: Be able to control the storms. Thunder, lightning and wind and command them at will.

Appearance when using Kekkei Genkai: Ruya uses her fans to help make stronger storms. She goes into a "Wind Witch" mode which helps her create more storms, faster and stronger. Her jutsus are also more powerful at this state. But the Wind Witch mode can only happen when Ruya is being pressured.

History of Kekkei Genkai: In the Shiraino clan, they are mainly a forest group. They harness the winds and lightning through their weapons to use. Forest Witches, (Wind Witch or Lightning Witch) are sealed inside of a destined Wind/Lightning user at a young age.

Drawbacks of Kekkei Genkai:
The Wind/Lightning Witch form is an "alternate" version of you. You and the Witch within you are different people, much like Jinchuuriki. However you are the one in control, even when you're in Wind/Lightning Witch mode.
When the witch within dislikes you, she/he can overpower you and try to/actually kill you.
Mastering your techniques with the Witch can take years and a lot of chakra. A certain few actually master the skills however.

Add a few more drawbacks to this and you're golden.