Your power(s) are sentient beings that can talk to you. They have their own personalities that reflect the nature of the power itself. For example, a fire power would be more impulsive, while a water power would be calmer.
While they cannot stop you from using them, your relationship with them affects how strong or weak they are. If you get along well with them, they will double your power. If you clash with them, they will half your power. If the power in question involves some kind of summoning, it will have the ability to control it independently from you. Your sentient powers are only voices in your head, they cannot take over your body or mind.
(Personified Power is independent of Hallucination and does not get stronger from it.)