Epic wiz king is a pretty horrible quest and needs to change. It is to long, boring and to repetitious. The effort to finish this quest compared to the raid is out of balance. I think there are a few problems that need fixing.
The first is time. Takes way to long to finish since you need to do all three towers to get the epic chest. You should only have to kill the wiz king to finish. Optionals should be, well optional. If you want all three end chest, kill all three else only kill the wiz king. You still have to find the correct tower.
The second problem is repetition. Skeletons, mummies, skeletons, mummies. The golems dont really break the monotony. Halt Undead makes the quest way to easy. Replace a few skeletons and mummies in the towers with some gnolls and ghouls. Give a random chance to the skeleton wizards to be immune to halt undead to spice things up. The skeletons are also to hard on your weapons. I used a maul with 2 tiers of adamantine ritual and it was broken 2/3 of the way through. Also make the optional bosses harder.
Bump the scroll drop rate. I guess this is true of most epics. I see maybe 2 scrolls per wiz king and that is with around 170ish kills per quest.