Reyhiem

Archbishop Reyheim was the most powerful religious figure in Farmus. As an archbishop sent by the Western Holy Church, he was (on paper, at least) on an equal position of power as the king himself given Farmus's adoption of Luminism as its state religion. That was just a formality, however; in reality, Reyhiem was more of a trusted right-hand man, taking his cues from the king.

Story
Reyhiem helped King Edomalis on his invasion against Jura Tempest Federation by providing Temple Knights alongside setting up a barrier that weakens monsters within the barrier.

He was captured by Rimuru alongside King Edomalis and Razen and was interrogated and tortured for weeks within Tempest.

He then pledge loyalty towards Diablo in exchange for his life and was sent to give a message to Hinata Sakaguchi from Rimuru.

Unfortunately for him, he was killed by The Seven Celestial Sages who were aiming to alter Rimuru's message to incite further conflict.