Find Lee, the Crafter on the left side of the Mountain Camp. Relics are a very rare and unique tier of item, unlike any that have come before it. Collect fragments from different sources to create a Relic. Take the pieces to Lee to combine them.
Crafting in Darza's Dominion is as easy as trading an NPC that shows up on your nearby character list. Taking certain items to certain NPCs will yield you different items. You can bring rare items, stacked gems and scraps to Lee for Relics, Dust, and Crates. Oyun will unstack gems for you. And Chad will... well, no one knows what he does just yet.