Death Aura

{{Spelldescription
 * icon        = Arcane_Spell_Death_Aura.png
 * school      = Necromancy
 * type1       = Negative Energy
 * type2       =
 * type3       =
 * type4       =
 * artificer   =
 * bard        =
 * cleric      =
 * druid       =
 * favored soul =
 * paladin     =
 * ranger      =
 * sor n wiz   = 4
 * cost        = 25
 * components  = {{V}}, {{S}}
 * metamagic   = {{Embolden}}, {{Extend}}, {{Heighten}}, {{Quicken}}
 * range       = Self Centered Standard AOE
 * target      = Self only
 * duration    = 24 seconds + 3 seconds per caster level
 * save        = None
 * sr          = No
 * cooldown    = 5 seconds (Wiz), 2.5 seconds (Sor)
 * description = In-game description (incorrect): Envelops the caster in a sickly aura of negative energy. Living enemies stepping inside the aura take 2d4 damage plus 1 per caster level every 3 seconds as long as they remain within it. Undead are instead healed by the aura, and friendly Undead don't trigger spell resistance. This aura can affect up to one creature per caster level.

Actual effects
}}
 * Testing shows that it only does 2d4 (+1 per 2 Caster levels, capped at +10 at level 20) every 3 seconds.
 * The spell will (while continuing its countdown) stop working when Unconscious; if brought back to consciousness the spell resumes its cycle (meaning if healed right after it reaches a multiple of 3, you missed the damage tick).
 * Only friendly undead (including Pale Masters and their skeletal summons) are healed by the aura. Enemy undead are unaffected (presumably to allow Pale Masters to self-heal in undead quests without inadvertently healing all of the enemies).
 * Duration only and not amount increased for caster levels beyond 20.