Koida 'Vadam was a Sangheili, and a member of the Vadam family and became one of their elders. He did not join in military service and so was not permitted to add the "-ee" suffix in his name. He sent several assassins attempting to kill Kaidon Thel 'Vadamee, but they failed. He ultimately lost his life when he attempted to kill Thel himself. Thel cut Koida's head off with an Energy Sword. The Kaidon then gave Koida's lineage the chance to leave or be killed.