http://ffxiv.gamerescape.com/wiki/Fi...r_Augmentation

You need to buy or craft a bunch of these to mimic the Warrior of Darkness. Take them to the same NPC in Mor Dhona you'd turn over Antique dungeon drops with the level 50 Artifact gear in hand. You get the dyable versions back.

Chest and pants take two augments, head, gloves, and boots take one, so you'd need 7 for a full set.

Dye them all Jet Black, and viola!