Crown of Corruption

The Crown of Corruption is a unholy githyanki relic in Dungeons & Dragons. Serving as the crown of Vlaakith CLVII, who created it more than 900 years ago before "the present", it is an artifact-tier magical item that is the key to her maintaining control over the githyanki.

(Gaz13, The Shadow Elves, had a Crown of Corruption before all that. It made you a lich if you put it on. So, don't do that.)

The Crown of Corruption appears as a slender, black-and-silver diadem, with rubies on its spires that look eerily like flickering eyes and which is reputed to occasionally twitch of its own volition.

It grants its wearer the ability to cast the spells Energy Drain (DC 23 Fortitude save to negate), Mass Suggestion (DC 19 Will save to negate) and Control Undead (DC 20 Will save to negate) at will. Additionally, by touching the corpse of a creature slain by the Crown's energy drain attack, the wearer can enact one of the three "Rituals" inherent to the Crown, any one of which requires 10 minutes to complete.

The Rituals of the Tl'a'ikith and the Kr'y'izoth transform the creature into one of these unique undead creatures; the rituals can be performed on any dead humanoid or outsider, but Vlaakith CLVII only uses these powers on her githyanki subjects.

The Ritual of Death's Ichor liquefies the corpse into a congealed ectoplasm that serves as powerful reagent in magical rituals; the death's ichor from a corpse can pay towards 100 XP per HD of the original creature when used as part of making an item or casting a spell that is fueled by experience points.

This artifact has only 30 hit points, but can only be harmed by a magical weapon that bears both the Holy quality and the Disrupting quality. If it is destroyed, then all Tl'a'ikith and Kr'y'izoth created by the Crown instantly perish in the bargain.