This character only appears in the El-Hazard Radio program, which takes place
after the first OVA series.
Salli is a being who has lived over 20,000 years and resides in a palace that is invisible to others. However, when Makoto and the others stumble upon the hidden place, Salli takes them prisoner.
She reveals that the palace houses an ancient device, whose purpose is for purifying El-Hazard, restoring it to how it once was some 20,000 years ago. She explains that after the great wars of the ancient past, there was much damage to the land, and thus the device was built to restore the air, the water, and the land.
Salli herself was created to stay with the device and protect it at all costs, which is why she is immediately at conflict with the others because she must destroy the possessed Fujisawa in order to protect the device, something that the others don't take very kindly to.
Salli is well equipped to fulfill her duties and is a powerful warrior, even handling both Shayla and Afura quite well. She can easily live up to the reputations of the other ancient devices, who were built with the purpose of either attacking or defending (Like Ifurita or Kalia).
After Makoto prevents the destruction of the device and defeats Myuun, the others ask Salli to come with them back to Roshtaria, but Salli's place is protecting the restoration machine. She was created by those who wished to return El-Hazard to its original beauty, because they had destroyed it. She will fulfill the promises of those people even if it takes several thousand more years. She then returns her palace to its invisible state and presumably lives on, keeping her promise.