Magic.
Everyone in this empire knew how important magic was in their daily lives. Just like how food gives nutrients to their bodies and makes them capable of working, magic is the most fundamental thing that exists in this world.
Just as how professor Klaus explained,
"The essence that naturally existed in our world back in the ancient era evolved into magic. However, this doesn't mean that the most magnificent form of essence was magic itself. No."
Klaus looked around his whole classroom. His expression then turned serious. He walked a few steps forward, then, with a sly grin, he whispered softly as if he was telling a secret.
Of course, this act caused his students to anticipate his following words.
