Common ProblemsCannot complete quest Throne of Tides: Azshara's Power, but I have the artifact Sharas'dal, Scepter of Tides
If you have already acquired Sharas'dal, you should be able to leave the scenario and complete Azshara's Power in Krasus Landing (the flight master area) in Dalaran. There will be a bubble at Krasus Landing, use it. This will teleport you to the class hall and mark the quest as complete.
The bubble is not the same as the portal to the class hall. It's near the crack in the wall.
If you can't locate the bubble, try to complete the scenario again. To enter the scenario, return to your Class Hall and interact with the teleporting bubble to go back to the Throne of Tides in the Abyssal Maw and repeat the scenario.
Once you have finished the scenario, do not use your hearthstone to leave the instance: use the portal provided. If you do not use the portal to leave the scenario, simply enter the scenario again and the quest will be completed.