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The Massive Possessor is a large, gaseous creature that bears some resemblance to the Darkball Heartless, sporting a similar, jagged mouth—albeit the Massive Possessor's is red—and glowing, yellow eyes. It is seemingly made up of black and dark blue and purple shadows.
The Massive Possessor's name clearly references its size, as well as its ability to possess inanimate objects.
Massive Possessors are more of an annoyance than they are a challenge. They have very little HP, and can be defeated easily through offensive magic, or even a physical attack. They will float around Roxas, however, slowly draining his HP. Dodge Roll can be used to escape this tactic. These Heartless will then proceed to split into several Possessors once they are defeated.