Lilith is a teacher at the Magic Academy, Lillith possess the ability to manipulate magical energy into her "Thema," a sort of basic will that she uses to create an effect. She is the one who introduced Arata to the magic world, she becomes one of his earliest allies and friends, watching and supporting him since meeting him.

Spoiler

Her real name is Azazel Lilith, daughter of a demon king who had her memories changed traveling through two worlds.