Here is the full list of all 14 Dark Dragonkin achievements.
Completed Dark Dragonkin Tutorial! (DEMO)
Completed Level 10 in the Demo!
Defeated Incendium in the Demo.
Completed Dark Dragonkin Tutorial!
Completed Level 10 Introduction Realm
Defeated Incendium in the Fire Realm.
Defeated Glacies in the Ice Realm.
Defeated Petram in the Earth Realm.
Defeated Fulgur in the Lightning Realm.
Defeated Aurum in the Treasure Realm.
Defeated Astrum in the Astral Realm.
Defeated Basileus in the Dark Realm