Duel Eknham was first introduced while both halves of its conjoined body were simultaneously strangling two doctors of the Penal Institute of Mental Health, planet Sedas, Sector 3550. Both personalities of this Siamese-like monster are killers; however the left side of Eknham is a brutal animal that relishes in carnage and gore. This barbarity stands in marked contrast to the right side, who favors a more delicate yet just as deadly approach to murder. During their murderous rampage within the hospital, Duel Eknham is surprised when a Sinestro Corps ring arrives seeking a new bearer based to instill great fear in the universe. Eknham is selected and both sides of the monster bicker over what hand should bear the ring.