Queen Azshara was the original Queen of the Night Elven race over 10,000 years ago. During the great Sundering, where she and her Highborne Night Elves attempted to use the Well of Eternity to summon Sargeras and his Burning Legion into Azeroth, she was thwarted by a number of heroes. When she failed, and Sargeras did not get through, the Well of Eternity imploded, sundering Kalimdor into the many islands/continents we know now.
But, when this happened, Azshara was able to make a pact with the Old Gods (Unsure which one/ones) in order to save her and her highborne, thus sealing there fate to live under the Maelstrom, and transform into Naga.
The entire Naga race still thrives underneath the Maelstrom, and its possible that it can serve as a rift for Sargeras to still come through. Were gonna have fun down there![]()