Ramiel is a fallen Watcher in the apocryphal Book of Enoch, one of 20 leaders, mentioned sixth. Ramiel means "Thunder of God", or God's Thunder, as the word itself is a combination of the words ra'am and God. Ramel belongs in a group of leaders that are comprised of 200 angels that are turned into Fallen Angels due to their taking wives, mating with human women, and teaching forbidden knowledge.
Before his fall, Ramiel was tasked into watching over the humans alongside his Grigori brethren, and provide thunderous sounds that accompany the lighting being conjured by the archangel Barachiel. It is also said that Ramiel was Barachiel's lieutenant before his fall, with two embodying the forces of thunder and lightning.
True to his name, Ramiel's voice alone is equal to the strength of thunder, along with his power being in the same league as the quaking sound effects of thunder.