The sphere is comprised of the pure negative, dark-blue energy of all the possessed people under Baby's control, making it an evil Spirit Bomb, of some sort. Unlike the Spirit Bomb, however, the energy is evidently stored within Baby, and can be replicated (and possibly amplified) at any time after the initial energy is absorbed. The Revenge Death Ball appears to be highly volatile as it will explode upon contact with anything, even the ground, making it unable to penetrate the surface of the Earth, like Frieza's Death Ball is able to, though it can destroy a planet upon contact, if he chooses to use the full power of the blast.
by HighClassChampion March 3, 2022