Bring an Abyssal Scepter to Bor Wildmane in Cenarion Hold.
Huum and I were just talking about you. He tells me you're just about ready to try your hand at fighting an Abyssal Lord!
I must tell you this is a very dangerous endeavor. You'd better bring backup. And I don't mean one or two of your friends, I'm talking about a top-notch, battle-ready fighting force. If your friends are as good as you, you might even defeat it!
If you do - and I'll want evidence, as always - I'll give you a truly great reward.