Diabolique is a Praetorian Earth archvillain.
Heroes face her:
- on the mission Part Nine: Find Statesman from Maria Jenkins (Levels 45 - 50)
- on the mission Stop Diabolique before she enslaves the spirits of the graveyard from Maria Jenkins (Levels 45 - 50)
- on the mission Search Infernal's torture chamber for any sign of Statesman from Maria Jenkins (Levels 45 - 50) (Flashback only)
- on the mission Rescue spirits from Diabolique from Maria Jenkins (Levels 45 - 50) (Flashback only)
Heroes and Villains face her in the following Incarnate Trial:
Prior to Introduction
- "This vortex is of far more interest than your insignificant whims or desires. If I have need of you then I will find you. Until then, test my patience no more. Now begone!"
Tammy Arcanus was born with great Magical powers on Praetorian Earth, just like she was on Primal Earth. Unfortunately they manifested very differently. As she reached adolescence she began exploring her powers before she was trained. She used astral projection to cast her spirit forth. So intoxicated was she by the new wonders that she was discovering she returned to her body too late to link with it. She watched helplessly as it withered and died without a spirit. Tammy's father tried to save her but he was too late to manage anything other than keeping her spirit bound to Earth. For his trouble Tammy blasted her father and turned him into her first spirit minion.
- Cerulean was Diabolique's mentor and lover back in the past when they were members of the Midnight Squad.
- Diabolique was responsible for the destruction of the Ravenwing Cabal which earnt the enmity of Sorceress Serene.