Setting An Example

High Shaman is an Elite mob that spawns inside a building east of the quest giver (59, 86) Most ppl research quests for coords and now day ppl post everything but that. And u dont have to impale him u can aggro him with any damage and just have him follow u back to quest giver.

Don't forget to tag the High-Shaman, don't just aggro by proximity.

IF you had NOT completed this quest after doing all the 3 visions and turned them in you can get the Blade item from the original NPC in the cave (Tranquil Wash) Wavespeaker Valoren <The Earthen Ring> / Horde Wavespeaker Tulra Legions Rest. She will have an option to "Revisit" the vision. Select it and you will be able to revisit ANY dream/vision.

IF YOU Completed the second vision or on the third vision, either way you WILL be required to complete all 3 visions in there entirity in order to go back and complete this quest. (See below on how to do this). THERE IS NO GETTING AROUND IT. Attempting to do otherwise will result in: "You have already witnessed this vision."

Now here is a few things you should know:
1) IF YOU HAVE the quest in your log and go to the second vision location and USE the blade and try to swim to the area the quest is located, YOU WILL BE teleported back to the second location & will recieve a message something along the lines of "you are going out of the vision area/zone..." and WILL realize your doomed to NOT complete this quest. HOWEVER indeed your not. YOU MUST ABANDON the quest and USE the Blade in that 2nd vision location and swim there in Naga form and omfg guess what.... that's right your not being teleported back to the vision location. You can now REACCEPT the quest and complete it.

2) YOU MUST Abandon quest to be able to swim to the other zone in Naga form.

3) The Zone NPC for the quest is 57/85 and the shaman to kite is in the rooom on the right of the quest giver. So close to him its ridiculously easy, press 2, turn and swim to NPC and it will complete automaticly.

4) The Blade Vision location is 29/78

5) The NPC to retrieve the Blade AFTER all visions were completed is: (Alliance) 49/57 (Horde) 51/62

6) IF you need to redo any quest the other 2 remaining vision zone coordinates is:
40/75 (First)
29/78 (Second)
33/77 (3rd) - This is up the stairs/ramp in a room and on 2nd Floor directly above the room entrance

7) You CANNOT use the blade provided for the quest your on to do other vision locations. You will receive this error: "You have already witnessed this vision.". What this means in lamest terms is:
You CANNOT use Vision 1 blade quest to acquire and activate Vision 2 or 3
You CANNOT use Vision 2 blade quest to acquire and activate Vision 1 or 3
You CANNOT use Vision 3 blade quest to acquire and activate Vision 1 or 2
You CAN use Cave NPC Vision OPTIONAL blade and activate Vision 1, 2, & 3.

Please Rate + if this helped!

Sorry for lengthy post. Did this cause found out it was a bigger issue than I once thought, and guildies constantly complaining about it pushed me to post this.

Edited for better clarification on lamest terms.
Edited to apply Horde information