Grencia Mars Elijah Guo Eckener (グレンシア・マルス・エリヤ・郭・エッケナー, Gurenshia Marusu Eriya Guō Ekkenā?) (born 2042, died 2071), nicknamed Gren (グレン, Guren), was a veteran of the Titan War. After the war, he was tried as a spy and imprisoned. He later moved to Callisto and played saxophone in the Blue Crow while also becoming involved in the illegal Red Eye trade. He was killed after confronting Vicious (Gren's war comrade) during a drug trade he had arranged.