Raven Curse could be obtained from the Fate Trio event.
Multiple black birds.
The other parts of this suit are Night Judgement, Lone Elite, Hunting Time, Void Chain, Eternal Duty, Abyss Faith, Ruthless Chase, Trial of Edge, Soul Axe, Devil Cry, Phantom Storm, Chaotic Moon, Withered Prayer, Night Graveyard and Unruly Soul.
There is an alternative version of the suit. It contains Night Judgement, Bloody Way Out, Abyss Faith, Devil Cry, Phantom Storm, Raven Curse, Chaotic Moon, Withered Prayer, Night Graveyard and Unruly Soul.