The Seraphim was an order of women created by Grand Patriarch Iblis Ginjo in 191 BG. Their purpose was to server and protect High Priestess Serena Butler. They are described something between Amazon warriors and vestal virgins; their members were carefully selected and assigned by Ginjo.
However assassins did infiltrate even these ranks. One such insidious attempt against Serena happened in 177 BG but the attempt was successful stopped by Niriem.