Here is the full list of all 36 Rune Knights achievements.
Complete your first quest.
Reach Level 10.
Reach Level 20.
Reach Level 30.
Equip Legendary items in every slot.
Craft an item with a legendary implicit mod.
Craft a Legendary mod onto an item.
Craft a Legendary Implicit Mod onto an item with a Crescendo.
Roll 4 slots on an item with an Endeavor.
Complete the quest Spreading Scourge.
Complete the quest Follow The Trail.
Complete the quest The Troll Lord.
Complete the quest A New Dusk.
Complete the quest A Resilient Adversary.
Complete the quest They're Everywhere.
Complete Avatar's Reach.
Complete Avatar's Reach on Captain difficulty.
Find a Legendary item destined for you.
Complete Avatar's Reach on Commander difficulty.
Defeat a Level 50 Invasion.
Defeat a Level 75 Invasion.
Defeat a Level 100 Invasion.
Complete the quest Ironhold's Ghost.
Complete the quest Through Iron Gates.
Complete the quest The Drowned Mines.
Complete the quest The High Arena.
Complete River Valtorin on Normal Difficulty.
Complete River Valtorin on Captain Difficulty.
Complete River Valtorin on Commander Difficulty.
Complete the quest Shadows of Ironhold.
Complete the quest Dark Heart of Ironhold.
Complete the quest Night's Silent Scream.
Complete the quest Shadowed Showdown.
Complete Wythmere City on Normal Difficulty.
Complete Wythmere City on Captain Difficulty.
Complete Wythmere City on Commander Difficulty.