Similar to Cragma, mob will spawn adds about every 20 seconds. adds aren't too tough, more annoying then anything, but if you can't burn him down quick enough they'll whipe group.
Idk, i think the horn thing is pretty cool, unless you have tower raid gear nothing group wise compares to the 30 Brass resonance. Which has become slightly more sought after since Venimor's Insult is brass based.