Villainess Level 99: I May Be the Hidden Boss but I'm Not the Demon Lord season 1 episode 12
Episode title: The Hidden Boss Battles the Demon Lord
At long last, Yumiella and her companions reach the Demon Lord's castle, but his power is so great that she's the only one who stands a chance against him. Then the Demon Lord tells them the true story of his connection to Valschein's royal family.
