For many years, Eris assisted Rezo in his quest to find a cure for his blindness and perform miracles. Over time, she developed feelings for him, though it remains unclear whether he reciprocated her affections. During this period, she aided Rezo in creating a clone of himself known as Copy Rezo.
In his desperation to restore his sight, Rezo left Eris behind in search of the Philosopher's Stone. Months later, Eris learned that Rezo had been killed by Lina Inverse, Gourry Gabriev, and Zelgadiss Graywords. At the time, she was unaware that Rezo harbored a fragment of Ruby Eye Shabranigdu within him, and that the trio had slain him to destroy the resurrected piece of the demon.
Grief-stricken and enraged by Rezo's death, Eris used Copy Rezo to place a bounty on Lina, Gourry, and Zelgadiss in the name of the deceased Red Priest. She also hired the bounty hunter Zangulus and created multiple additional copies named Vrumugun (in the novels, she dispatched Rahanimu and Dilgear alongside Vrumugun). Her plan was to lure them to Sairaag where she could exact her revenge. However, before she could execute her scheme, Copy Rezo betrayed her. Realizing too late that Copy Rezo was not the true Rezo, she met her demise when Copy Rezo obliterated her, leaving no trace behind.
In the manga, Eris only appears in flashbacks, confirming that Copy Rezo had already killed her before the Slayers reached Sairaag. Her full name is mentioned exclusively in the light novels.
(Source: KanzakaDex, edited)
