Ladybird

Ladybird (レディバード) is a character introduced in Souyaku Toaru Majutsu no Index.

Appearance
Ladybird has the appearance of a 13 or 14 year old girl. She has long bright red hair, and red mechanical eyes, which sometimes display images. She is barefooted and wears something like a racing swimsuit, with an orange and black coloration resembling that of her, as well as several belts around her thighs.

Operation Handcuffs Arc
During Operation Handcuffs on December 25th/Christmas, when Hasuu was captured by Anti-Skill before they could hijack a vehicle, Ladybird used the prison transport to bypass checkpoints before breaking Hasuu out at School District 1's general station. The two then proceeded towards the station's communication control box so Hasuu could infect and bring down Anti-Skill's network, with Ladybird killing any Anti-Skill officers and Anti-Skill Aggressors in their way.

Seeking the counterfeiter Perfect Film in order to acquire a counterfeit passport, the two went to School District 6, where Ladybird slaughtered Vacuum Piece's group, decapitating him after he had confirmed that their target was up ahead. After disposing of the corpses, Ladybird kept an eye out for other people who were also after their target with instructions to kill. He spotted and attacked Hamazura Shiage and Takitsubo Rikou who were after a fake ID as well, and Benizome Jellyfish, who was after a scoop. After Benizome stunned Takitsubo in order to escape while Ladybird focused on the weaker target and get her pictures, Ladybird was prevented from killing the two by Frillsand who interfered with her sensors and caused her to lose track of them, acquiring a minor head wound as a result.

When the counterfeiter was killed before they could obtain a counterfeit passport, Ladybird accompanied Hasuu as they returned to his hidden lab in the trash piles of south School District 23 and had maintenance performed on her. She later attacked Hamazura and Takitsubo, after they discovered the lab and were using its equipment to decrypt Perfect Film's hard-drive, but was forced to retreat after a mortally wounded Vivana Oniguma interfered.

Ladybird and Hasuu arrived at the Vanishing Tunnel after Frillsand's slaughter of those heading for the escape route and as the ghost was about to kill Hamazura and Takitsubo. Once Hasuu managed to neutralize Frillsand, Ladybird killed Drencher Kihara Repatri by deflecting his bullet when he fired on them in defense of the Child Errors with him. Ladybird subsequently fought Hamazura, who was supported by Aneri, while also wondering why Hasuu wanted the children and how she had used a different esper power than before.

As she hit her limit, she was horrified to learn of her brain-devouring nature from Hasuu, having previously believed that his work in creating her would mean children would no longer be sacrificed for esper development research. Overcome by the hunger for a brain, Ladybird targeted the nearby children, while Hamazura fought to stop her. Eventually, he managed to use a smokescreen to trick her into mistaking a gas drum he had put clothes on for one of the children, and shot it when it was taken into her back. The resulting explosion destroyed Ladybird, whose decapitated head appeared to be smiling, as she would never have to kill again.

Abilities
Classed as an android, Ladybird is a machine comprised of artificial parts which have been built up into the form of a human, created from scratch without a human base. Although her body is modelled on that of a human, the materials and machinery making up the body, Kihara brand products and dark side technology,   grant her capabilities far beyond a normal person. She is strong enough to hurl a 40-50kg person with ease and wield a blade too heavy for a normal person to lift. When bipedal, her horsepower can rival a V12 engine at maximum RPMs, with an even higher top speed on all fours.

Being a machine, Ladybird is susceptible to strong electromagnetic waves.

Brain
Although Ladybird largely fits the definition of an android, being constructed from purely mechanical parts, there is one aspect of her which does not - Ladybird incorporates pieces of brain matter extracted from human bodies. Her body's structure is modelled on that of a human and she has a similarly designed brain. (セルロースナノファイバー‎‎‎) was used to create delicate wires even thinner than cranial nerves, however unlike in a biological brain, leaving them in their active state causes them to automatically replicate. If they run out of room, they will try to forcibly fold themselves up for space. The cerebrum's frontal lobe was noted by Hasuu to be particularly troublesome. In order to counteract this, Ladybird must take a foreign object (i.e. human brain matter) into her brain so that the resulting rejection reaction will constantly provide the right amount of damage to her brain and keep it at the desired size.

Ladybird has automatic extraction organs, long and translucent, which emerge from a hatch on her back. When Ladybird needs to take in new brain matter and is at the right distance from a suitable target, they will wrap around her victim and drag their target into her back for extraction. This cruel design has been compared to that of an autonomous iron maiden. When Ladybird needs new brain matter, leaking a dark liquid from her mouth, nose, eyes or ears shortly beforehand, she experiences an immense hunger which overrides her will.

Being modelled after the structure of a human body and with the structure of a human brain (with mechanical processing noted as conceivably being able to 'observe' waves or particles like a human brain does), Ladybird is capable of using an esper ability. This ability changes whenever new brain matter is introduced due to changes in the rejection and damage pattern, with Ladybird having been shown using a telekinetic, then a pyrokinetic, and then a wind-based power. Rather than being a brain given a body like the esper cyborg Rensa, Ladybird is described as a body given a brain.

Equipment
Ladybird wields a 60cm machete known as Left Arm (防御の剣（レフトアーム）). It is made of the artificial element Saintium (セインティウム‎‎‎), which has a metallic bond strength 56 times greater than depleted uranium. As such, the blade can easily stop a warship's armor-piercing artillery and be used to deflect bullets, though it is too heavy for a normal person to wield.

As well as a smartphone on each shoulder, Ladybird has several belts around her thighs with skinny tubes which contain rolled-up silicone keyboards and clear bottles filled with thick, clear liquid. The liquid in the bottles is a discharge machine oil (放電機械油) which reduces the frictional wear on her joints, as well as a room temperature superconductive fluid which allows her to safely release her excess energy Ladybird's clothing is designed to help radiate heat to cool her off, as well as providing air and blast resistance.