Styx
Generation V · The river of oaths
Eldest and most eminent of the Oceanids, goddess of the black river that winds through the underworld. When Zeus called the gods to his side against the Titans, Styx came first, bringing her children Zelus, Nike, Kratos, and Bia, and as her reward the gods swear their unbreakable oaths on her water. Even an immortal who forswears her stream lies breathless for a great year and is exiled from the councils of the gods.