The Ritual of Renewal did not require the energy of a Luxan in order to be activated – although an Orican would likely not consider using any other creature. When the Orican Nilaam cast the Ritual of Renewal on Ka D'Argo and returned herself to youth, she accidentally reached through D'Argo to Moya and drew the necessary energy from the Leviathan instead of from D'Argo himself... and even Moya proved not to have enough energy to uphold the Ritual for long.