Guren

is a kunoichi who appears in the second Naruto Shippūden filler arc. She is the female leader of Orochimaru's subordinates. She uses.

Three-Tails Arrival filler arc
To aid him in final preparations for his plan, Orochimaru sent Kabuto to fetch Guren (much to Kabuto's disapproval). Upon approaching her domain, Guren attacked Kabuto with a barrage of her deadly crystal release jutsu. Kabuto manages to evade all of her attacks and accuses her of knowing all along who he was. Guren smugly states she just wanted to make sure Kabuto was worthy of being Orochimaru's right-hand man. Upon returning to Orochimaru's current hideout, she was put in charge of having hundreds of test subject prisoners battle each other to the death.

Eventually after the majority of the prisoners killed each other, Guren stopped the battle to make them her henchmen. When most of them decided to kill her and escape Orochimaru, Guren without hesitation took killed them instantly with her crystal jutsu. The remain henchmen, Rinji, Gozu, Kigiri, Kihō and Nurari, instantly decided to follow her without question.

Personality
Guren has shown to be a very mysterious konoichi, apparently preferring to keep to herself despite having a strong loyalty to Orochimaru. Her loyalty is not unlike that of Kimimaro as she too was at one point a willing canditate to become Orochimaru's next body. During her introduction, she quickly showed herself to be a remorseless and sadistic person. When told by Kabuto that several prisoners would be fighting to the death, she became ecstatic to hear there would be a slaughter. She is devotedly loyal to Orochimaru, but has a terrible relationship with Kabuto.

Abilities
Guren possesses a unique ninja art; the Crystal Release. It is unknown if this is a unique kekkai genkai or secret technique. By using this power, Guren can summon and manipulate crystal in a number of manners such as creating crushing walls or unique shuriken. This ability is presumed very powerful as Orochimaru at one point desired it for himself.

Trivia

 * There have been arguments as to if Guren's Crystal Release is a sub-element similar to Haku's Ice Release and the First Hokage's Wood Release.
 * On the back of her coat, you can see a small white lotus flower as a reference to her name.
 * Guren has been a candidate as Orochimaru's new body but in the end, she didn't make it through the selection. For this she still regrets.