Ectoplasm is a form of energy present in all humans, when the human's mind ascends to the Ghost Zone, the ectoplasm comes with them. if the ghost is morally good, their ectoplasm will react to their positive emotions and desires and form into their own personal paridise. If the ghost is morally bad however, the ectoplasm will do the opposite and form into the ghost's version of hell based on their negative emotions of deepest fear, for this reason, the Ghost Zone is entirely composed of ectoplasm. When Eidolon summons ectoplasm fom the Ghost Zone, he summons it from the areas of the evil, so as to not deprive benevolent ghosts of their personal paradise. Also, the ectoplasm he summons loses it's subatomic malleability and can only take it's simplest form: white energy that can be used for binding, telekinesis, freezing or force exertion. It is unknown how the ectoplasm that Ariel uses in her ectoplasmic grenades takes a sticky, semi-solid form.