Prior to the [[Horus Heresy]] and before [[Konrad Curze]]'s death, '''Acerbus''' acted as a [[Captain]] in the [[Night Lords|VIII Legion]]. He seemed to have a long term rivalry with [[Zso Sahaal]], the first company captain. '''Acerbus''' claimed that [[Night Haunter]] foresaw Sahaal's disappearance and allowed it to happen, in order so that his 'worthy witterings' would not obscure his vision. '''Acerbus''' also claimed that Night Haunter wished for his legion to sow fear in his name and eat the terror of the Imperium, which conlficts conflicts with Sahaal's account of Night Haunter which claimed that Curze used fear as a tool, but it never was the ultimate goal.