Will of the Whole Misaka Network

The Will of the Whole Misaka Network, abbreviated as the The Whole (総体 Sōtai) in the original text, is a character introduced in Shinyaku Toaru Majutsu no Index.

She is a single organic system, a thought entity, created from the gathering and consciousness and egos of 20,001 Sisters. A non-corporeal character, she possess other Sisters in order to give out timely advice to the protagonists in times of need.

(Source: Toaru Majutsu no Index Wiki)