Studies
The Divine Academy was bigger than a single massive main hall. Countless halls were spread across Keiros, filling the planet with the training grounds and resources needed to accomplish a few things. First, the Divine Academy was where all prospects with enough potential to become true powerhouses were trained. They received resources and the necessary Ancient Ruins to unlock their hidden potential.
But the most important aspect of the Divine Academy were the laboratories. The Divine Academy had multiple laboratories used for two particular tasks: To produce Blood Incursion and inject it into the students sent to the Divine Academy.
Michael knew of multiple places like this one, but the Divine Academy was the biggest. That was also why so many Divine Lifeforms protected it.