Shooter Insane Black Rock
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.
Insane Black★Rock Shooter retains much 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. Being another form of 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.
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 express 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.