The Night Serpent

The Night Serpent is the only demi-god to have ascended *after* the death of the Eight, rather than during. A servant of the Dark Lord, the Night Serpent assassinated the Lady of Twilight and assumed her power. It was this assassination, as well as the disruptive affairs (romantic and political) of the demi-pantheon itself, that led to The Retreat. He acted as the Dark One's primary vessel after the former's imprisonment by the self-sacrifice of the Makers.

Some Sahuagin are known to still venerate the Night Serpent, or at least his memory, making him the only member of the demi-pantheon to still have active followers, despite his being 14 centuries dead.