Guren

is a kunoichi who appears in the second Naruto Shippūden anime-exclusive arc. She is the female leader of Orochimaru's subordinates. She uses the unique Crystal Release brand of jutsu.

Background
As a child, Guren came from a small village where she was shunned by others because she had unique powers. Later, Orochimaru appeared and destroyed the entire village single-handedly. He was intrigued by Guren's powers and offered for her to come with him. Guren chose to follow him because she envied his power.

At some point, Orochimaru sent her to destroy another town in order to test her potential. However, after doing this she passed out, due to the over-usage of her powers. When she woke up, she found herself to have been healed by a woman, who she would later discover to be Yūkimaru's mother. Guren returned to Orochimaru but, in order to keep his approval, she was forced to kill the woman. Wanting Orochimaru to accept her, she sadly killed the one who had cared for her.

Guren quickly became one of Orochimaru's most powerful and loyal subordinates. Eventually, she was offered the chance to become one of Orochimaru's future vessels. When Sasuke Uchiha defected from Konohagakure and Kimimaro was no longer a suitable vessel for Orochimaru, Guren became the next best choice in Orochimaru's eyes. Unfortunately, by the time she arrived, Orochimaru couldn't wait any longer and instead chose Gen'yūmaru. Feeling no longer of use to Orochimaru, Guren went into isolation.

Personality
Guren has shown to be very mysterious, apparently preferring to keep to herself despite having a strong loyalty to Orochimaru. 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. Guren is also shown to be vain by the fact that when she used her Crystal Release: Jade Crystal Mirror, she looked at herself and said, "Lovely, as always." She has also shown to be very proud. When Naruto offered to carry her, she was embarrassed because she felt it was shameful.

She is devoted to Orochimaru to an almost obsessive state. This devotion was so powerful that she fell into despair when she learned she would not become Orochimaru's next vessel, isolating herself from the shame. It has also been shown she has a terrible relationship with Kabuto, as the two argue often, trading scathing remarks. Later, she meets Yūkimaru, and at first, she finds him peculiar and somewhat irritating. However, when Yūkimaru became ill, she cared for him, watching over him for an entire night, until she fell asleep from exhaustion. When she woke up, she found that she was alone - and went searching for Yūkimaru, who she found nearby outside under a camellia tree. She then develops a sort of friendship with him as she crystallizes a flower and tells him that the flower will never wither as long as she is alive.

Since coming in contact with Yūkimaru, Guren seems to be having conflicting emotions. While part of her still wants to be accepted by Orochimaru as his next vessel, another part of her seems unable to let go of the bond she has made with Yūkimaru to the point of protecting him even from Orochimaru's right-hand man, Kabuto. The emotions seemed to have become more confusing for her in her first one-on-one confrontation with Naruto, who stated bluntly how horrible and selfish a man Orochimaru really is.

After realizing the truth behind her past and how it connects her to Yūkimaru, Guren feels even more compelled to protect him, out of guilt and repentance for her past sins, as well as love - wishing to become an almost surrogate mother to the boy, to replace the mother she killed. She even goes so far as to turn her protection to Naruto, as they faced off against the small Three-Tails clones within the beast's stomach, telling him she would protect him to the death if he would watch after Yūkimaru. This is a great change from her previous interactions with Naruto, whereas she was stand-offish and combative, she becomes quite friendly with Naruto. Subsequently, Guren has also begun to have doubts over remaining loyal to Orochimaru, due to her grief over the horrible things she was made to do in his name, and the damage and pain he has caused Yūkimaru and herself.

Abilities
Guren possesses a unique ninja art: the Crystal Release. It is not clear if it is a kekkei genkai, however Guren made it clear to Kakashi that he couldn't copy her techniques with the Sharingan but Tsunade also indicates that there were rumours of this ability although it was never confirmed during the ninja wars. This could indicate that there have been others with this ability but it was rare or rarely used since she had little knowledge of it. By using this power, Guren can summon and manipulate crystal in a number of ways, such as creating crushing walls or unique snowflake-patterned shuriken. Guren may even stand and ride upon her crystallized constructs. Guren's Crystal Element seems to be closely related to the Earth and Wind Element, seeing as how it was vulnerable to Kakashi's Lightning Cutter and Tenten's flame-enveloped weapon.

It is stated by Kabuto and by Kakashi that she can crystallize moisture in the air, therefore giving her an infinite source of weapons. The density of this power appears to be very high as even the Wood Release was unable to penetrate it. The Crystal Release ability is presumed to be very powerful as Orochimaru at one point desired it for himself.

In times of desperation, Guren is also able to convert a small portion of her life energy to access extra chakra reserves to allow her to continue fighting at full strength for a short period of time.

Guren's taijutsu skills are also rather high as she was able to fight on even grounds with an expert like Kakashi, dodge multiple Rasengan attacks from Naruto, and fight Lee and Tenten simultaneously. She is talented at noticing weaknesses in her opponent and using diversions, shown in how she kept the rest of Team 8 busy fighting her clones while she takes Hinata hostage. In addition, Guren also has good senses and is a keen observer. She was able to tell when Kakashi and Yamato were near and she was able to conclude that the Three-Tails was trying to protect its eye just by watching the way it defended an attack.

Part II
Boo!

Trivia

 * On the back of her coat is a small white lotus flower, as a reference to her name.
 * To date, Guren has shown the most techniques of all filler characters.
 * She has shown to be able to use one-handed seals similar to Haku.
 * Her name means 'crimson lotus'.
 * In the omake in Naruto Shippūden episode 134, Guren made a cameo along with Yūkimaru on Commemorating the 350th episode.

Quotes

 * "Heh heh, I love the scent of blood."
 * "You scums are lucky to be with Orochimaru-sama!"
 * "Well, what about you guys?! You discovered Yūkimaru's powers and now you want him! After all, taking the Three-Tails means that Konoha will be in possession of enormous military power!"
 * (To Rinji) "If you ever betray me, you'll die."
 * (Referring about Sasuke to Naruto) "I met him at Lord Orochimaru's base. He's quite the scary one."
 * (To Naruto) "''As you said, I hurt Yūkimaru's soul in a way that I could never make amends. I have no right to protect him. It's over for me! But I will protect you, even if it costs me my life!"
 * (To Yūkimaru) "I promise to protect you with my life!"
 * (To Naruto) "He is the place to which I can return!"