Slithering among her minions to ensure their loyalty, there is one reigning matron of the waters of Outland. Taking it upon herself and all of her naga underlings to control the Coilfang Reservoir and Outland's waters for Lord Illidan, Lady Vashj sits comfortably upon a throne underneath what's left of Zangarmarsh's waters. If you seek to challenge her reign over the water you must first find her...
Along the paths to Lady Vashj you may encounter one of her prisoners: a water elemental by the name of Hydross. He is currently held in stable form only by two pillars of purification energy so if you can lead him away perhaps he will kindly allow you to pass. Don't count on it. It seems he has no choice in the matter and will guard control of the water with his life.
"I cannot allow you to interfere."
The waters of the Serpentshrine Cavern may seem plentiful and enticing to fish from, but be cautious. A deadly secret also lurks in wait for the unsuspecting adventurer. The waters will boil in frenzy if the area is threatened by adventurers such as yourself. Perhaps you can fish up some kind of secret to calm the waters?
". . ."
While some believe that the naga take asylum from their enemies by instead serving Lord Illidan in their natural element of the Cavern, the Cavern itself is an asylum for one: Leotheras the Blind. He was cast away by his mentor, Illidan himself, after being driven mad by the trainings in the art of demon hunting and now finds himself captured and banished by the those under Vashj's rule. He seeks only his freedom and his demon seeks power over all. This conflict does not spell well for those nearby when his banishment is released.
"We all have our demons..."
With a title like Fathom-Lord it is not difficult to tell that Karathress makes his home in the waters. Perhaps a partner of Lady Vashj, as would be fitting to be the Lord and Lady of the sea, it will not be possible to take her down without first vanquishing him.
"Her... excellency... awaits!"
Few sea giants remain on Azeroth (or elsewhere) since the land was raised many millennia ago and their duties fulfilled. The few that do remain are wise yet chaotic, as any dutiful servant and master of sea should be. Among these giants is Morogrim Tidewalker. Once challenged, a sea giant rarely backs down or shows mercy, and there are rumors that to Murlocs, they are the ultimate gods...
"By the Tides! Only the strong survive."