A kid's mistake gets his heroes killed, and he inherits their weapons as a funeral gift. That guilt doesn't fade, it fuels every battle, every new ally he collects, every step toward the strength he should have had from the start. Beet carries five dead people's final choice on his back, and the show never lets you pretend that's a clean story about growing stronger.

A dark century grips the land, and people suffer under devils called Vandels who command monsters. The Vandel Busters hunt these devils, and the Zenon Squad is known as the strongest on the continent. Young Beet dreams of joining them, but through his fault the squad falls to the Vandel Beltose. As they die, the five busters pour their life force into their five Saiga weapons and hand them to Beet. Years later, Beet sets out as a young Vandel Buster to carry out the squad's will and end the dark century. This season picks up where the first series left off.