
It used to be a currency of its own in the player Trading Post before it was made untradeable. For me the fastest way was to buy them cheap.

You should easily get 100 of them by the time you have the 400 dragon coins for a complete soul dragon. Just get all the golden souls you see while farming dungeons. Dragon Coins can also be found in Dragon Caches, acquired from the Dragon Coin Digest and Dragon Hoard Deposition legendary tomes or be purchased from the store in packs of 5 for 750 cubits. Focus on getting to level 30 and 5k-10k PR before spending time on dragons.

They can be used to craft Dragon Souls and Dragons at the Dragon Crucible in the Hub or to buy goods from Luxion of the Golden Hoard.

These chests can be obtained from lair and dungeon chests uncommonly, and can also be purchased through the Store for 50 Credits each (Bought either by itself, in a bundle of 11 with a bonus Chest, or in a bundle of 110 with a bonus 10 Chests and a Golden Chaos Chest). Dragon Coins are rewards from hourly challenges. Chaos Chests are lootboxes that contain many items such as resources and collectibles.
