Open all “Key of YXZ” Dreadnaught chests
To open all nine “Key of” Dreadnaught Chests you have to find as first a Wormsinger Rune. You will get the rune from killing Hive in Dreadnaught (randomdrop) After you get the rune, use this rune at the machine in Hull Breach.
Now kill the incoming Hive and Boss and you get a Wormfeeder Rune. To transform the Wormfeeder Rune into a key you have to kill 50 Enemies in Dreadnaught (Cabal or Hive) without dying, after that you obtain the key. Which key you get is completely random.