Testament

Testament (学習装置)|Gakushū Sōchi (Tesutamento)|lit. "Learning Device"}} is a machine designed by a genius biopsychologist, Nunotaba Shinobu, that is used to install information into a human's brain. Notably used for the Sisters Project under the supervision of biopsychologists.

Appearance
The machine appears in a form of a big capsule, large enough for an ordinary middle school girl to fit in, though there are probably other variations of size depending on the person. The seal for the machine is transparent in order for observers from the outside to fully view the recipient. Inside, the subject wears a helmet which is connected to tubes and wires, though another Testament machine showed the helmet covering the eyes and ears of a Misaka clone which probably produces the same effect. Outside the capsule, several tubes and wires are connected to the machine and probably leads to the bank where the information to be installed is stored.

However smaller versions of the machine exist, which can be used to install specific information to a user such as a computer virus, as with the case with Kihara Amata.

Use and Operation
The subject lies down inside the apparatus, here, the helmet is inserted unto the subject's head. By sending out electrical signals into the brain, the machine can input large amounts of information in a short period of time by affecting all five senses of the body. Using the machine, information such as speech, logic, motor functions as well as the personality and emotions of the subject can be installed.

Level Upper Arc
The Testament machine is first mentioned by Kiyama Harumi during the Level Upper Arc, where she mentions its existence as a comparison of the Level Upper to Uiharu Kazari.

Sisters Arc
The machine is prominently featured in the Sisters Arc. Here, the machine is physically seen for the first time and how it is used to install information into Misaka 9982.

Three Stories Arc
The machine is mentioned by Yoshikawa Kikyou as a requirement as so the virus installed into Last Order – the command center of the clones – can be removed as it will send a command to the Misaka Network to kill all humans. However, due to time constraints, Accelerator is forced to use his vector powers to mimic the Testament machine, and remove the virus by rewriting the code.

Amai Ao may have used a Testament machine to install a virus into Last Order prior to the events of the arc.

Academy City Invasion Arc
With Vento of the Front invading Academy City and utterly crippling its infrastructure, Aleister Crowley decides that it would be a great opportunity to use Fuse=KAZAKIRI. Here, he orders Kihara Amata and his Hound Dog unit to capture Last Order to install a virus into her that would force the remaining Radio Noise clones to initiate the activation of the Imaginary Number District and manifest Fuse=KAZAKIRI into Academy City.

Amata successfully does so, which severely injures Vento of the Front for being a magician upon the installation of the code into Last Order. Though the code remained in Last Order, Index manages to stop it from working by using a song after realizing that the laws that allowed the manifestation of Fuse=KAZAKIRI could be found in one of her 103,000 grimoires.