Insane Black★Rock Shooter

Insane Black★Rock Shooter is another form of Black★Rock Shooter. She does not appear in the OVA. However, she does appear in the animated series as a major antagonist. In the anime she refers to herself as Mato Kuroi's "other self" as she is a different version of Mato's real "other self", Black★Rock Shooter. She first appeared on huke's blog and his pixiv account.

Original Concept
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 that has the black bikini top, 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 is the same as that of B★RS. She wears a black crown-like object with a white cross design which wraps around her left twintail. A few chains wrap around her hair and around her waist.

Her weapons of choice are vastly modified weapons of Black★Rock Shooter's ★rock Cannon and Black Blade, named Insane Cannon Lance and Insane Blade Claw respectively.

Black★Rock Shooter (2012)
Insane Black★Rock Shooter retains much or all of her original design, except for the chains that wraps her hair due to her "crown" being redesigned like a helmet. The armor on her body seems less, as it only covers the part below her chest. Her chain is now at her back which connects to her Insane Cannon Lance. Like B★RS, I.BRS has a spikier hairstyle, does not have any scars on her midriff, and her trademark fangs are not shown. Her broken star symbol seems different too.

Like all of the "other selves" in the anime, her purple eyes have a circular pattern in them. However, unlike all the other selves who have white pupils in their eyes, including Black★Rock Shooter, Insane Black★Rock Shooter has red pupils. While Black★Rock Shooter only ignites her eye flame at certain points during battle, Insane Black★Rock Shooter's eye flame is constantly active.

Her weapons have both been redesigned as well.

Black★Rock Shooter (2012)
I.BRS, like B★RS, is mostly silent, but also quite stoic. Like all "other selves", she hardly says anything. She is absolutely merciless in battle, perhaps even more so than some of the "other selves;" she presses her assault even after sustaining severe personal injury.

Interestingly, although "other selves" claim that they have no emotions, Insane Black Rock Shooter does seem to experience some emotion - including surprise and fear - at certain points. She also appears to enjoy a good battle, as she is seen grinning insanely when she is about to strike Strength, and again when Mato stands up to her and brings out the ★rock Cannon in its rapid-fire incarnation.

When the battle is not particularly challenging for her, I.BRS rarely shows any emotion and maintains a blank expression. An example of this is when Black★Gold Saw severely injured her right arm, yet she didn't react at all. She also seems to disregard any injuries that she receives due to her high regenerative abilities. Examples of this are when she simply tears off her injured arm during her fight with B★GS and when she willingly shoots herself in the leg to prevent Mato from hindering her.

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 willingly accepts, with her left eye purging blue flames. Mato merges with Black★Rock Shooter, who had stabbed Dead Master. In Mato's point of view, she finds herself in the presence of Yomi instead, and saw Black Blade went through her, causing Mato to have a mental trauma. Mato's condition appears to have affected B★RS as well, and ignites her blue flame. Seeing the corpse of the Dead Master, she suddenly became unstable and ignites a red flame, which then merges with her blue flame to create large amounts of purple flames, and turning her blue eye color purple. B★RS' iconic star breaks, matching Insane Black★Rock Shooter's iconic broken star.

Spikes start to penetrate into Black★Rock Shooter, and purple light glows from her, turning her into her iconic insane form. Nearby, Black★Gold Saw is startled by the sudden change in the area and looks behind her. Both ready their weapons and lunge at each other. Within Insane Black★Rock Shooter, Mato writhes in pain as Black★Gold Saw cuts Insane Black★Rock Shooter's right arm. Insane Black★Rock Shooter simply tears off her injured limb and Mato shrieks. She then went limp as Insane Black★Rock Shooter and Black★Gold Saw continue to fight. Insane Black★Rock Shooter uses a chain to replace her arm and hurls her Insane Cannon Lance at Black★Gold Saw. The Cannon Lance begins firing rapid-fire purple blasts while in mid-air. Black★Gold Saw avoids the attack and knocks the Cannon Lance into the ground, but the Cannon Lance deploys a turret on its underside and shoots her arm off, forcing her to retreat. She opens a rift in the floor and slides through, closing it behind her. Insane Black★Rock Shooter takes Black★Gold Saw's fallen King Saw and uses it to tear open the rift to follow her. Black★Gold Saw turns to fight again, and uses her watering can to summon several armed hooded figures to attack Insane Black★Rock Shooter.

Insane Black★Rock Shooter simply blasts through the hooded beings as she slaughters her way to Black★Gold Saw, but when she heard Saya's voice pleading to Mato, Insane Black★Rock Shooter stopped her blade right over Black★Gold Saw's head. A reaction is triggered in Mato and suddenly Insane Black★Rock Shooter is swatted away by an unseen force and pinned to a bunch of pillars.

After Saya's flashback, Insane Black★Rock Shooter screams in rage, smashes free from the pillars and attacked Black★Gold Saw again while Saya continued to plead to her. Insane Black★Rock Shooter showed no further reaction to the pleas of Saya and was in position to impale Black★Gold Saw with her own King Saw. At the last moment, the blade was jettisoned to the side where she would have killed Black★Gold Saw. It is revealed that she was pushed aside by none other than Strength. Strength's massive fists send Insane Black Rock Shooter flying into a pillar. She quickly recovers and charges Strength, but Strength slams her Ogre Arms into the floor of the Otherworld, breaking open a fissure to her world, and escapes into it with the unconscious Black★Gold Saw. Insane Black★Rock Shooter leaps into the fissure and chases after them. While they leap between areas, many colors pass by.

In the tumult, they reach Strength's world. Strength puts Black★Gold Saw's body away, and she and Insane Black★Rock Shooter continue to fight. Insane Black★Rock Shooter uses her Cannon Lance to fire at Strength, but Strength manages to avoid the attack and punch Insane Black★Rock Shooter with her Ogre Arm, knocking her several yards into a wall. Insane Black★Rock Shooter follows up with her Insane Blade Claw, but Strength simply grabs the sword, breaks it with her sharp tail and throws her away. Insane Black★Rock Shooter tries to resume her assault, but Strength switches places with a large block and attacks Insane Black★Rock Shooter from behind, crushing her against the block. The scene ends with her bringing both of her fists down on the heavily injured Insane Black★Rock Shooter.

However, Insane Black★Rock Shooter regenerates and overwhelms Strength. Due to her regenerative abilities and armour, she is able to withstand both Strength's machine guns and gatling guns. Eventually Mato manages to delay Insane Black★Rock Shooter, allowing Strength to wound her, but Insane Black★Rock Shooter manages to get her Cannon Lance in front of her leg and activate the rear vulcan, wounding Mato. Insane Black★Rock Shooter is not troubled due to her high regenerative capabilities. Insane Black★Rock Shooter regains control of the fight, but Strength suddenly seems to go insane and overpowers her, grabbing the Cannon Lance and throwing Insane Black★Rock Shooter away. The two have another shoot-out, vulcans against machine guns, and Strength is again overpowered. However, she seems to enjoy this and manages to grab the Cannon Lance and punch Insane Black★ Rock Shooter in the face. She commandeers the Cannon Lance and intentionally activates all the vulcans at once to wound herself. The world they are fighting in is consumed by fire and "Strength" reveals herself to be the real Yuu Koutari, who switched places with Strength in the Otherworld. Insane Black★Rock Shooter uses her Cannon Lance to propel herself over the flames to safe ground and charges at Strength, but Yuu activates several more Ogre Arms attached to her back and whacks Insane Black★Rock Shooter repeatedly on the block she is standing on and throws the Cannon Lance away. As Insane Black★Rock Shooter lies on the ground, Yuu and Strength recount their story to Mato.

Yuu continues to smash Insane Black★Rock Shooter on the block she is standing on. Insane Black★Rock Shooter attempts to retaliate, but Yuu overpowers her. However, Strength tries to destroy herself to stop Yuu, freezing Yuu in place. Insane Black★Rock Shooter pulls her Insane Cannon Lance back with her chain and goes in for the kill, but Mato refuses to let her do it. Mato's resolve causes the area inside Insane Black★Rock Shooter to fill with light and both Mato and Insane Black★Rock Shooter are transported to Black★Rock Shooter's world, with Mato in the normal Black★Rock Shooter's body. Mato apologises to Insane Black★Rock Shooter for making her bear all her pain and suffering. Insane Black★Rock Shooter speaks to Mato, saying the she is fine with accepting Mato's pain as her "other self". Mato tells her that she does not want to hurt anyone, not even Insane Black★Rock Shooter; she wants to be hurt by herself. Insane Black★Rock Shooter merely grins, drops her Cannon Lance and begins pummelling Mato with her fists, causing her to bleed red blood. Insane Black★Rock Shooter tells Mato that her wounds won't heal as quickly as the "other selves" would. Mato collides with the ★rock Cannon, inexplicably embedded in the ground and Insane Black★Rock Shooter asks her why she won't use it. Mato says she never wants to use it. Insane Black★Rock Shooter attacks her again, forcing her to grab the cannon and block the attack. Mato continues to shield herself with the cannon, while Insane Black★Rock Shooter tells her it is "unfair" to get hurt without hurting others. Mato accidentally manages to non-fatally stab Insane Black★Rock Shooter in the side with the cannon, and feels the pain of hurting someone. Insane Black★Rock Shooter simply breaks the cannon on her knee and resumes her assault, injuring Mato severely and breaking one of her legs. While Mato struggles on the ground, Insane Black★Rock Shooter notes that the attack was "hardly anything" compared to the battles between "other selves". Mato still finds that she can't hurt someone. She reflects on the picture book she read when she was younger and how the bird in the book died. She has a vision of the bird regaining its colours and gathers her resolve, summoning the ★rock Cannon in its tri-barelled gatling gun form (as well as healing her damaged leg), and begins firing at Insane Black★Rock Shooter. Insane Black★Rock Shooter smiles sadistically and fires back with her Insane Cannon Lance. The two then start a massive shoot-out, but are evenly matched. Insane Black★Rock Shooter manages to destroy the ★rock Cannon again, but Mato, with the help from all the "other selves", summons a giant ★rock Cannon and aims it at her. As Insane Black★Rock Shooter looks on in fear, Mato fires a giant rainbow-coloured beam at her, annihilating her and her Cannon Lance. After Insane Black★Rock Shooter was destroyed, Black★Rock Shooter returns to her normal state.

Abilities
I.BRS may have great powers of regeneration as she was shown reattaching her right arm without any worries and uses it as if nothing happened to it at all; the arm can still pull the trigger of Insane Cannon Lance mid-air after being ripped off. I.BRS also doesn't feel any pain, no matter how fatal the opponent's attacks are. I.BRS can also resist Mato's ability to control I.BRS to a limited extent enough to injure herself and thereby injure Mato.

Trivia

 * Her blood is purple, compared to Black★Rock Shooter's blue blood.
 * I.BRS is one of the few characters based on B★RS herself. The others are Mato Kuroi, Black★Rock Shooter Beast, and White Rock Shooter.
 * 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 B★RS turns into I.BRS from undergoing emotional trauma while merged with Mato. This suggests that I.BRS is related to B★RS's mental state and is not directly related (or related at all) to Black★Gold Saw.
 * Even though I.BRS was the main antagonist, her purple eyes and flame only appeared at the very end of Episode 5, and she didn't make a physical appearance until Episode 6.
 * In Episode 8 of the anime, I.BRS refers to herself as Mato's other self. This is probably because she is a transformed version of B★RS and not a separate being from B★RS.
 * This would also explain why I.BRS' trademark fangs are not shown in the anime, as Black★Rock Shooter does not have fangs.
 * The shouting expression of WRS in the figma may be based on I.BRS, seeing in that expression that she bares fangs, much like I.BRS.
 * Like Black★Rock Shooter in the OVA, I.BRS also lost her sword in combat. However, while the OVA incarnation of B★RS lost her sword in the fight with Black★Gold Saw, I.BRS' sword was broken by Strength.