Earn an Honored faction with the Hydraxian Waterlords, then talk to Duke Hydraxis in Azshara.
Hydraxian Waterlords: 0/1
If you truly wish an allegiance with us, then I invite you to wage war on our foes, the servants of air and earth and fire. Each defeat you heap upon them will weaken their foothold here, and further prove your adherence to our cause.
The campaign will be long, but if you persevere then your glory and honor will be great.
