Instructions
Go to Dantooine.
Enter Khoonda. This is the large building to the south of where you landed.
Talk to Terena Adare. She will talk to you about Vrook. She also gives you access to the sublevels of the Enclave.
Enter the Enclave courtyard from the exit in Khoonda. There is an exit in the northwest and northeast corner of the map.
Enter the Enclave sublevels. The entrance is located in the northwest corner of the courtyard.
Locate the bodies of the mercenaries killed by Vrook. These are located on the east side of the northernmost passage.
Press the "A" button while targeting the body of one of the mercenaries to examine it. This step must be performed for Vrook to appear later.
Go to the Crystal Cave. This is located in the southeast corner of Khoonda.
Follow the left path until you reach a room with Vrook and several mercenaries.
Talk to the mercenaries. No matter what you choose, you will eventually need to kill the mercenaries and Vrook will escape.
Exit the Crystal Cave. Azkul will talk to you as soon as you do.
Say "Okay, I'll help you." This will cause you to side with the mercenaries. You will not be able to kill Vrook and get the Jedi Master Robe if you side with Khoonda.
Talk to Azkul again. Tell him you are ready to attack Khoonda. You will have to fight Vrook in a one-on-one fight.
Kill Vrook. The strategy you need depends on your class, feat and Jedi power selections. Repeatedly use Flurry on him if you are a lightsaber combat focused character. Use your most powerful damage attack powers if you are more force-combat-focused.
Press the "A" button to examine Vrook's body after killing him. You will find the Jedi Master Robe on his body along with a lightsaber.