Note: Copied from VS Battles Wiki
Multiple personality - The ability which allows to have several different personalities in your mind. This ability has a number of advantages and a number of shortcomings.
- The division of roles - Each personality can be strong in some ways and is only activated when there is a need for its services.
- Collective Intelligence - One head is good, two is better, and if one head has a million consciousness at once, with a sufficient level of organization, they can replace a strategic headquarters or scientific institute.
- Change in body - Switching between personalities may also change the body, getting different (and likely necessary) skills and abilities.
- Mental resistance - The presence of a large number of consciousness allows resistance to mental influences, because even if one of them succumbs to external control, the other personalities immediately bring the wayward personality to its senses.
- Disorganization/chaos/power struggle - If each personality pulls control towards itself, a situation may arise in which control of the body randomly shifts from one mind to another, which obviously does not benefit the whole person.
- Increased complexity of control - Usually if there is one dominant personality, it has to constantly monitor all the other consciousness, which requires considerable effort, and in certain situations severely limits other abilities (because there is no mental direction at the other faculties of the body).
- Problems with memory - Because the personalities are still autonomous, when you switch from one to another, the memory information may be lost. Or else, one of the personalities may unknowingly erase the memories that are important to the another.