Cecilia was once part of the Presider Team that served under Principal Dormin. She belonged to the Pig Five. They were a group of powerful Presiders that had the Devourer Suit. But unlike Presiders that served a Principal, the Pig Five were noted to be one that had 'very special treatment.'
While Principals could not attack Presiders and wage war against them, there were other means that they could interfere using the power to see the dimensions and even the future.
Presiders would even see themselves dying in death due to how Principals could simply plant seeds that would have dangerous manifestations in the future. In her life, Cecilia defeated two Mid-Tiers and devoured them thanks to the preparations that her former master had said.