???

??? is the subconscious manifestation of Mob's enormous psychic power that was consciously repressed in order to appear normal. ??? was formed as a result of Mob bottling up his emotions and refraining from using his psychic powers due to "that" incident in Mob and Ritsu's youth.

Appearance
As a subconscious entity, ??? does not have a true form or appearance though its presence in the outside world can be perceived by Mob's eyes whiting over, his hair flaring wildly and a dark-coloured overwhelming aura encompassing him.

When viewed inside Mob's mindscape, ??? appears to be a completely featureless version of Shigeo.

Personality
As the subconscious manifestation of Mob's repressed psychic power, it views itself as Mob's truest existence, something which has been alluded to by other characters.

It only ever manifests itself in the physical world when Mob loses consciousness in a situation of extreme stress, whereupon it proceeds to either destroy the cause of the problem or carry out Mob's current desire. It explains that is does this for its own sake as it can do what it wants to do.

Teruki Hanazawa Arc
??? first appeared after Mob was knocked out from Teruki Hanazawa strangling him. ??? proceeded to massively overwhelm Teruki, before destructively lifting up the destroyed school building's debris high into the sky.

Keiji Mogami Arc
??? next appeared while Mob was inside of Keiji Mogami's mental world after Mob's mental body was eaten up by Mogami's rampant spirits. After manifesting, ??? released its colossal psychic power in destructive waves, annihilating Mogami's mental world, freeing both Mob and Minori Asagiri from his possession.

???% Arc
??? then surfaced after Mob was knocked out after being hit by a car on his way to meet Tsubomi. Awakening because it had predicted it would be needed for such an important moment, ??? destructively continued on the journey to meet with Tsubomi, laying waste to the city and anyone who got in its way. After encountering Ritsu, Mob was finally able to confront ??? head on, where ??? explained its desires and motivations for the way it acted as well as revealing it would take control of Mob. Mob then explained why what it was doing was wrong and told it that he would come to accept ??? as a part of himself. At that, despite fearing rejection from Tsubomi, ??? eventually accepted and assimilated with Mob, signifying Mob's acceptance of the immense psychic power he possessed.

Powers & Abilities
As ??? is the subconscious manifestation of Mob's repressed psychic power, it represents the full and unrestrained extent of Mob's psychic power. As such, it is capable of all the feats Mob is capable of, on a much greater and destructive scale. For example, ??? has a much greater ability in absorbing psychic energy, being able to absorb the energy from other espers and the atmosphere around him without the need of getting into close proximity to the source.

???'s feats include effortlessly defeating Teruki Hanazawa and destroying Black Vinegar Mid's school building before raising all the debris high into the sky, entirely destroying Keiji Mogami's mental world (thus freeing himself from it and Minori Asagiri from Mogami's possession) and laying waste to a large area of Seasoning City on the way to meet Tsubomi (effortlessly defeating Teruki Hanazawa and Toichiro Suzuki in the process). It is undoubtedly true that in this state, Shigeo is the strongest esper in the entire series.

Notes & Trivia

 * ??? is implied to have first manifested during an incident where he passed out and awoke to find knocked out bullies and an injured Ritsu. It is this event, and the witnessing of ???, that long traumatised Ritsu into fearing and being jealous of his older brother's psychic power.
 * Despite being born from and a part of Mob, it seemingly exists separately within Mob as destroying the vessel that contains it, such as when Mob's body was destroyed by Keiji Mogami, unleashes it.
 * In the MP100 X Hito Kui crossover, it was shown to be possible for ??? to manifest physically while Mob is 'conscious' or while Mob is trapped in a place where he cannot use his psychic powers, as both were the case while Mob was in dream-world of the "Devourer", implying that ???% is not a part of Mob's regular psychic abilities. XXXX (presumably the "Devourer" himself) commented that "[Mob] is no regular person".