My Mentor is the First Guardian 31

Wilbur Palmer sealed the swarm behind a gate and slept a thousand years for it. He wakes to a world that buried his name. His formula carries a stranger's patent. Every student he trained died holding a line he never reached. The swarm never left. It learned to steal human faces, open schools, pass certification exams and walk the streets as citizens while he slept. So Wilbur picks up his blade and teaches ordinary people to awaken, because a city that knows its own face cannot be conquered from inside.