since i coded this one i'll go ahead and answer this one
on revenants
there is a 1/12 chance of it casting a revenant when doing a random spell, smaller chance if the creature is doing a combo.
(its no coincidense you get hit with corpse skin before receiving poison based damage spells(strangle/poison strike/pain spike), for example.)
The bug is in the VengefulSpirit.cs file/spell, because the spell derives its target from the person who casted it.
RunUO never anticipated necro spells to be cast by NPC's and thus it is possible that the caster gets deleted (is dead) before the target is dead.
( players never get deleted, they only get dressed differently and the color of the screen changes, we call this being dead )
when that happens, since it uses its casters targetting (which no longer exists) it goes silly and cannot damage players. you may notice it running after you but doing no damage, it basically just picks a target at random, most of the time that is another NPC.
there are two ways i/we/someone can fix this:
1) make it so that the vengeful spirit uses a target reference of its very own, not its caster
2) make it check it its caster still exists, else: self-destruct
3) both
TL;DR: the bug is not in the AI but in the spell
on the drain
the whole design if this champ is that it cannot be done with a pack, not easily anyway.
the more pets you pull out, the more HP it gains per drain. (it searches a radius for viable targets and drains form everyone equally)
Either use tactics, or a single tank pet.
Kronus was designed to keap a TEAM of vet players with insane gear entertained for at least an hour or two, never ment for just 2 players and their pets.
TL;DR: this is intended behavior, but the amount of drain he and/or the death wisps do can be easily edited.
