Kino suspected that Aleph's control over Eren's body was a case of demonic possession.
After all, Aleph's presence within Eren aligned with the characteristics of such possession. However, such occurrences were typically reserved for demonic rankers who had forged Faustian Contracts with their respective demons.
As far as Kino knew, Eren was not a demonic ranker. This made Aleph's seizure of Eren's body all the more perplexing and mysterious to her.
"A demon, huh?" Aleph chuckled upon hearing Kino's question. "Well, something along those lines. Though technically speaking, I'm far beyond the likes of Demon Princes," he replied playfully, a mischievous tone in his voice.