{Based on the Book, 'The First Diplomat: Ez'}
History is a merry-go-round that revolves around the same wheels and the same places. So the saying that history will repeat itself is the right thing.
Like deja vu for immortals, they see the same story repeated in human civilization.
Well.. It's not that humans don't learn from history but they find new ways with the same goal.
At first, Mana God used mana to become a god and asked humans to worship them. Humans are enslaved because of their ignorance.
But The Great Human War destroyed them. Then the era of Mana Gods end.
The surviving mages discover that the key to strength and power is mana mastery. So they hide it and destroy the rest.
They also know that humans are creatures full of curiosity. If humans find out that they can have superpowers like them then they will continue to look for ways to become stronger.
They hide in the shadows and control the rulers behind the scenes.