Considering the nature of the Prophet of Perfection and the Great Leviathan Fracture, there were several noticeable similarities.
But it couldn't be confirmed directly.
It was merely a hunch that Cetas had.
No.. It couldn't be. Why would a Profane Deity disguise themself as a Great Leviathan?
It was weird.
The Prophet of Perfection's goals are weird.
Nevertheless, he continued to read the book and study about several Leviathans that are located in the seas. The book contained a lot of detailed accounts regarding those that roam near the continents, however, it still wouldn't account for the Leviathans that are hidden in the depths.
For example, the three Leviathans that they've just encountered were unknown ones that have not been logged yet.
If Reid knew about them then he would share information regarding their Zeal and their weaknesses.
But alas, he couldn't.
So, until sunset Cetas read and studied.
