Possession

"You seem to be smarter, but he has the best body," The demon king inside Seadrei's body said. "While you two came from the same planet, you are from different species, and the nature of your power is truly interesting. To think that an unknown lifeform would help you all like this. This overseer person is truly amusing. You people are lucky."

Even if Seadrei had been naive enough to allow his body to be taken over by an enemy once again, he wouldn't have revealed such sensitive information in such a short span of time. The fact that the demon king inside Seadrei's body possessed not only his physical form but also the knowledge of his techniques and strategies raised several concerns.

It became obvious that the demon king had swiftly accessed and assimilated Seadrei's wealth of knowledge, including the details of his abilities and techniques. This implied a level of proficiency in manipulating Seadrei's mind and extracting information that was alarming.