Belnistrasz cares not for politics; he cares not if anyone's affiliations are for either Horde or Alliance. He is more interested in squelching direct and dire threats to all the races. And he has found one in Razorfen Downs.
Belnistrasz says: All right, stay close. These fiends will jump right out of the shadows at you if you let your guard down.
Belnistrasz says: Okay, here we go. It's going to take about five minutes to shut this thing down through the ritual. Once I start, keep the vermin off of me or it will be the end of us all!
If attacked:
Belnistrasz says: You'll rue the day you crossed me, <mob name>
During the ritual:
Belnistrasz yells: Three minutes left -- I can feel the energy starting to build! Keep up the solid defense!
Belnistrasz yells: Just two minutes to go! We're half way there, but don't let your guard down!
Belnistrasz yells: One more minute! Hold on now, the ritual is about to take hold!
Belnistrasz yells: That's it -- we made it! The ritual is set in motion, and idol fires are about to go out for good! You truly are the heroes I thought you would be!
From end quest text:
The image of a great-winged dragon fills your mind. A more graveled version of Belnistrasz's voice speaks directly to you.
Indeed mortals, you are the heroes I had hoped you would be. Thanks to you the butchery these beasts were perpetrating is a thing of the past. My faith in mortals such as yourself has been once more renewed. Take this as a reward befitting of a hero.