Toi'Viral was a reformed Marilith who ran a cease-fire church in Diimgard called The Temple of Harmony. The temple joined various races to worship the gods in harmony, these races were the kobolds, the orcs, the goblins, and the elves. The church stood for centuries until the mid BR era, when the church was ultimately destroyed in a draconic attack. This led Toi'Viral to craft the Seven Arms of Sin and ultimately wish the dragons away.
For two hundred years, Toi'Viral took trips to various elemental planes and studied artifact crafting to build her Arms of Sin and get her wish.
Her wish created inescapable demiplanes that the gods were able to use to banish Tiamat and Bahamut. Without the support of their gods, the dragon race quickly diminished and were soon entirely extinct from the realm, bringing the Holy War to an end.
After deploying her dragon-destroying wish, the genocide had an adverse effect on Toi'Viral. The Kobolds in the area knew the source of the wish and quickly hunted her down. After robbing her of most of her weapons, they left her to die. Instead of fighting back, she decided to bar herself from the outside world, using another wish to create a factions of massive elemental guardians who would guard her tomb. Her only companion was LightnIngot, one of her Arms of Sin. The other 6 arms were dispersed around the region by the kobolds, never to be reunited.
Being a demon, Toi'Viral had no natural life span, and spent over 600 years in solitude in a magical chamber on the site of her temple's ruins.
The ruins of the temple were thought to have been lost in the Lonely Mountains of Diimgard, but in 691 PR it was rediscovered by the combined scholars of Dolmvay and Elin Barad, both cities having been under the attack of the great dragon Corduth, who was hunting Toi'Viral's ancient weapons.
When the temple was rediscovered, it was found that an enchantment only allowed females to see Toi'Viral, and using her charms, Iris snuck past the guardians and visited Toi'Viral in her chambers, providing the first company for the Marilith in many years. When Toi'Viral realized her chambers were under attack by dragons again, she ended her stasis, and gave over the last of her magical weapons to complete the set.
After the wishes were all used up, and her temple rediscovered, Toi'Viral would then spend her life attempting to fix the divides among the ancient races.