Once Yakumi Hisako's consciousness has been transferred to the Shading Computer that uses the AIM diffusion fields as a medium, she refers to herself as an AIM thought being, and that she has stepped into the realm of Kazakiri Hyouka and DRAGON. What differentiates her from Kazakiri Hyouka is that she can communicate with others in such a state, and has shown no way of being able to physically manifest herself. Moreover, she has shown no inclination of having physical form and rather wants to "transcend" being a part of the AIM diffusion fields, becoming even greater than Kazakiri Hyouka and DRAGON, using either the water of the oceans or the air of the world for the Shading Computer's medium, which had allowed her to become an AIM thought being in the first place, but as well as trapping her in the one place it is concentrated, Academy City. While being an AIM thought being, she has no body.
After Kamijou Touma destroys her AIM thought being form in one strike, her consciousness becomes an information life form. In a way, she becomes free from the bounds of being an AIM thought being, but still even more limited as she uses her "scent" that was being emitted by the swarm of man-eating cockroaches that destroyed her body earlier as the processor for the Shading Computer that allowed her to manifest herself.
With regards to Artificial Angels and DRAGONEdit
It is unclear on how similar an AIM thought being is to Artificial Angels or beings such as Aiwass (DRAGON), since the latter has existed before the foundation of the City, or if they can be termed as AIM thought beings as well. Hisako notes that after becoming an AIM thought being, she has "stepped into the realm" of both Kazakiri Hyouka and DRAGON, most likely referring to their existences that requires the use of the AIM diffusion fields of Academy City. One clear distinction between an existence known as an AIM thought being and them is that Kazakiri and Aiwass cannot communicate and interact with other people except in the event that special circumstances are affecting them. For example, Kazakiri Hyouka was able to interact with Index only after she was mysteriously brought into the world and away from the Imaginary Number District gaining a physical form, most likely by Aleister Crowley's manipulations. Aiwass on the other hand requires a special code inputted into Last Order in order for him to be brought into the world. All three beings can observe the "real world."
As to having a "body", Kazakiri Hyouka, the moment she gained "consciousness," had a body inside the Imaginary Number District, this is unlike Hisako who had no body to speak of before Fremea Seivelun hijacked the Shading Computer. Though it is unclear as to whether she had an "information body" e.g. a body made of information, because Fraulein was able to eat most of her "data" in a few bites.  Aiwass is presumed to have had a form or at least to have existed even before the founding of Academy City, which would explain why Aleister was able to modify him and to give him defense mechanisms against suicide and opponents, considering that Aiwass has displayed no inclination to defend himself. As for the the artificial angels of the Imaginary Number District, though they may not have control or awareness over themselves, they retain a body that can be manipulated by Hyouka.
It can be concluded that the beings that require AIM diffusion fields to exist have properties similar to an AIM thought being, but it is not wholly what defines them, as they are not a mere consciousness that exists through AIM. Also, as Aiwass explained, he can go to a deeper plane of existence, which is most likely neither Academy City nor the Imaginary Number District.
- ↑ 1.0 1.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 07 Chapter 4 Part 1
- ↑ 2.0 2.1 2.2 Shinyaku Toaru Majutsu no Index Light Novel Volume 07 Chapter 4 Part 11
- ↑ 3.0 3.1 Shinyaku Toaru Majutsu no Index Light Novel Volume 07 Epilogue
- ↑ Toaru Majutsu no Index Light Novel Volume 07 Chapter 2 Part 1
- ↑ Toaru Majutsu no Index Light Novel Volume 06 Epilogue
- ↑ Toaru Majutsu no Index Light Novel Volume 19 Chapter 4 Part 1
- ↑ 7.0 7.1 Toaru Majutsu no Index Light Novel Volume 06 Chapter 4 Part 3
- ↑ Toaru Majutsu no Index Light Novel Volume 19 Chapter 4 Part 5