Have the minions that Zemouregal summons deals Necromancy damage. Having to deal with all 3 styles from enemies that have an insane health pool in larger groups and without much telegraphing of their existence until you realize you are taking a lot of damage is not fun. It also doesn't make sense that the conjures deal melee, ranged, and magic damage when conjures from our character and even from Rasial deal Necromancy spirit damage.
Have antipoison have a small effect against the poison pools and put on a green overlay on our screen (like AoD/AG ice overlay, but green) if we're standing on it. Another small improvement to telegraphing and overall messiness of the poison pool mechanic.
Give a text box warning when an Empowering zombie spawns. So many people are not even aware of the empowering zombie mechanic, where letting him reach Vorkath increases his damage output.
Spawn healer and shielders at a fixed location. Playing hide and seek with single-tile monsters in a boss fight where there is already too much going on in the screen is not fun nor is it indicative of skill. If Empowering zombies spawn at a fixed location, Skeletal shielders and ghost healers also should, since all three of them as classified as "special conjures" that directly support Vorkath (and are immediately dismissed when Vorkath dies)
Reduce Zemouregal's voice lines and just reserve them for when he's about to use an ability. This would be a simple way to telegraph his attacks.
I may still be underestimating how much work would be needed to implement these, but I assume they'd be easier than a full rework of the boss.
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