I completed this Event April 28, 2008
On zoning in the 4 humans(8 minions), 3 litches(6 minions) and Vesthon spawned. Have the raid in position before you zone in.
We had a shadowknight aoe agro the minions and a chanter lock down the mezable adds.
The human mobs and litches did not move from their position.
Direct the raid to kill the human mobs as quicky as possible then kill the litches. The minions will despawn when their "boss" dies.
We pulled Vesthon away from the bones a bit and killed him.
Dracolitch spawned and killed him.
Raid was 24 people (level from 70 to 80) mixed gear up to elementals and single group/bazaar SoF gear. Sk held agro on minions, Chanter mez'd, Rangers/Monk tanked the human and litch mobs. Do not be afraid to try this fight it's not even close to as scary as it was at 65 with elemental gear and 60 in raid ;)
On fail you can retrigger on entering zone (not sure on time limit or if there is one)