Granbell Rosso/Chronology

Saint-Monster Confrontation Arc
He incited the betrayal of the Clerics of the Seven Luminaries against Luminous in order to eliminate both Demon Lord Rimuru Tempest and Hinata Sakaguchi who were both in the way of his granddaughter's plan to conquer the human world through economics.

He faked his death as "Gran" by pretending to be killed by Nikolaus Spertus when Luminous and Rimuru foiled his assassination attempts.