Roy Valentine served as the stand-in Demon Lord for Luminous and the people of Lubelius believed he was their true emperor.
Roy Valentine has taken the mantle of Demon Lord in public so that Luminous can keep her identity a secret, but it is exposed by Veldora at the Walpurgis.
With her secret revealed, she sends Roy back to Lubelius early while she takes her seat at the table.
Fully aware that the demon lord is away, Laplace sneaks into the palace in Lubelius but he is stopped by Hinata Sakaguchi and has to run away.
Laplace had tried to explore the holy shrine at Lubelius once before but he was thwarted by Roy’s older twin brother, Louis.
Avenging a friend
Laplace had advised Clayman to be careful in his quest for power but Clayman got ahead of himself and ultimately died at Rimuru’s hands.
When Roy returns to Lubelius, he encounters a fleeing Laplace and taunts him about Clayman’s death.
When Laplace faced Louis, he barely got away with his life but this time he was fueled by the anger at Clayman’s death.
He takes on Roy and before Roy can use his unique skill, Laplace pulls his heart out. He shows that almost as strong as a demon lord and shouldn’t be taken lightly.
Luminous, Louis, and Hinata all partly blame themselves for Roy’s death until Luminous says that they mustn’t dwell on it too much.
Laplace and the rest of the Moderate Harlequin Alliance along with Yuuki decide that their plans have been upended by Rimuru so they need to restrategize.