Nightchord drops from mobs, named and trash (in some KOS raid zones)
Relic drops from the same mobs, but only drops a generic pattern (silk, leather, chain, plate) for each armor slot. ONce you have the pattern you need 3 gems (different for each archetipe and armor slot). With the pattern and gems you have to go to Sol Eye, a NPC by the Forge of Ages trades that stuff for your armor piece. No tradeskilling involved, just turn items for your armor.