Referred by the nickname "Lady of Light." Part of her cruelty mandate seems to be enjoying the suffering of others. The society of Scyllithene Drow, as existing before the Third Hell War, were run by Priestess of hers who despised her. Casual cruelty and innate violence permeated the society.
Scyllith was not was not well regarded by her Infinite Order colleagues, perhaps due to her antipathy to the sufferings of others. To obtain her help, I.O. colleagues such as Heilo were obliged to present gifts and flattery. Scyllith also had the habit of adopting failed or abandoned experiments of her colleagues, many of these becoming demons in hell. Scyllith's own creations were spectacularly bereft of looks and beauty for the petty purpose of elevating her own vanity.
Scyllith conducted most of her research and experiments in a separate dimensional domain. This domain was transfused with her personal magic (Infernal) and later became Hell. Some of the residents of Hell still adhere in their allegiance to her, resisting Ellial who usurped Scyllith.
Scyllith's personal magic, the Infernal, is uniquely corrosive. Demons themselves are not beings of Infernal energy, but rather those who evolved in spite of Infernal energy.
At some point in the past, the Pantheon made a bargain and worked with Scyllith. This cooperation appears to have come during the Hell Wars and after the downfall of the Infinite Order in the Elder War. Vesk and other Pantheon gods have indicated that Scyllith, despite having escaped the fate of the Infinite Order, was perhaps the worst example of them.
Before the Third Hell War Scyllith was a regular participant and day-to-day manager of the Scyllithene Drow society. Surface dwellers are told that Scyllith was confined to the underworld after her expulsion from Hell, but this confinement seems to have been dramatically upgraded sometime after, or during, the Third Hell War. Currently Scyllith cannot regularly manifest and her existence has been specially diffused and muddled. She was able to appear at the I.O. machine in Irvoi only because the trancension field editor was active.
In fact, the Pantheon, although having done business with Scyllith on multiple occasions, regards her as particularly dangerous. Scyllith was apparently banished to her own domain (Hell) either by the Elder Gods or by the Pantheon early in its existence. The Pantheon regards Scyllith's release from Hell back to the mortal plane as one of Ellial's more outrageous acts. It is unclear what strife occurred during her original confinement to the underworld. So too is there uncertainty as to what caused it to be necessary to specially muddle and confine her existence.
At some point before current events but long after her expulsion from Hell, Scyllith was dealt a massive defeat by Arachne Tellwyrn and Ellial working together. This defeat apparently resulted in the razing and burning of Scyllithar, the capital city of Drow who worship her. As Scyllithar was the known holding place of the golden temporal egg that was Araneid's not-dead remains (and a massive font of power), this razing of Scyllithar may have resulted in Scyllith's loss of her hold on Araneid. Araneid's remains are now apparently under the control of Avei, probably under one of her temples.
Someone has been using Scyllith's credentials to access I.O. facilities. Given her current muddled state, this access has involved bouncing Scyllith between transcension fields such as the one at the Puna Dara fabrication plant. One of her priests has been assisting Archpope Justinian using Scyllith's credentials to access and manipulate I.O. machines.
It is unclear how far someone can get using Scyllith's credentials. Despite her non-alignment with I.O during the Elder Wars, Naiya apparently opted to lock Scyllith out of the I.O. systems as well as the rest of the Order. This lockout was ultimately a critical part of the demise of the Infinite Order, but Scyllith was able to survive through uncertain means. Avatar 02 locked the Puna Dara fabrication plant into a security lockdown which apparently is beyond the ability of either remaining member of the Infinite Order, Naiya and Scyllith, to affect.
Apparently Scyllith's presence, when concentrated, is easy for other gods to detect. Such that her followers have trouble avoiding the attention of Pantheon Gods and servants when Scyllith is invoked,
Some have described her as having a pathological need to cause pain, even to the detriment of herself and her own plans.
As a god she is amused by attempts to betray her and encourages them.
She has an unexplained connection to Arachne Tellwyrn.
Scyllith apparently enjoyed both Reign of Chaos and World of Warcraft (Azeroth). On the original Earth, she lived in Toronto. She grew fruit in her garden while the rest of Earth was being destroyed by climate change.
Omnu was apparently Scyllith's gardner. It is unclear if he worked for her on the original earth or on the current planet.