Insane Black★Rock Shooter

Insane Black★Rock Shooter(インセインブラック★ロックシューター, Insein Burakku Rokku Shuutaa) is another form of Black★Rock Shooter. She does not appear in the OVA, however she does appear in the animated series. Her bladed weapon does appear in the OVA however. She first appeared on huke's blog and his pixiv account.

Appearance
Compared to Black★Rock Shooter, Insane Black★Rock Shooter has purple eyes with a flame of the same color emerging from her left eye and fangs. Her outfit is a black armor, covering her chest, left arm and legs. Her jacket is a torn black cape and her entire right arm is a robotic appendage holding a vicious blade. Her hairstyle resembles the same as that of BRS, she wears a black crown-like object with a white cross design which wraps around her longer lock of hair. A few chains wrap around her hair and on her waist.

Black★Rock Shooter (2012)
When Yuu sent Mato into the Otherworld, Mato was asked by a voice from nowhere if she is willing to face all of the pains and sufferings that she have gone through and will not run away from them. Mato decides then her left eye purged blue flames. Mato merges with BRS and she stabbed the Dead Master to the chest. Seeing in her point of view, Mato finds herself in the presence of Yomi, and saw the Black Blade went through her. This caused Mato to have a mental trauma. It seems that Mato's condition affected BRS as well, and ignites her blue flame. Seeing the corpse of the Dead Master, she suddenly became unstable and ignites a crimson, red flame. She then ignites a large amount of purple flames and her eye color suddenly changes..... Then the white star breaks.

Trivia

 * A popular fan theory holds that Black★Gold Saw and Black★Rock Shooter "fused" to become Insane Black★Rock Shooter (evidence to support this can be "blue+red=purple"), but this has not been confirmed in any way. A drawing has been made for this theory.
 * In the 2012 anime, it appears that BRS turns into I.BRS from undergoing emotional trauma while merged with Mato. This suggests that I.BRS is related to BRS's mental state and is not directly related to BGS.
 * I.BRS is one of the few characters based on BRS herself. The others are Mato Kuroi, BRSB, and WRS.
 * The shouting expression of WRS in the figma maybe based on I.BRS, seeing in that expression that she bares fangs, much like I.BRS.
 * The name of her weapons are Insane Cannon Lance and Insane Blade Claw.