The OP Lich is a Returnee

On January 20th, 2020, an explosion rocked the International School in Seattle, Washington. That explosion brought magic to the world, spreading across the globe in what would come to be called the Awakening. All around the world, people began to develop magic powers, some of them even turning into creatures of myth like elves and dwarves.   With magic came monsters, and other threats to the world. Some of those who had power took up the call, and became adventurers or heroes, fighing back the monsters. Others let their newfound powers go to their heads, becoming villains. Many turned their powers to crafting, and melding magic and technology. And a few began delving into the secrets of magic for knowledge's sake alone.   But the blast that kickstarted the Awakening did more than just bring magic to the world. Twenty students, all in the same class, disappeared that day. No trace of their remains was ever found, and no one else in the building was so much as injured. People began calling them the Lost Sleepers, twenty souls who would never Awaken like the rest of the world had.   Forty years after the Awakening, one of them returned.