Skyrise

Skyrise is a Phoenix that has come to the Serpent Isle to counter the imbalance.

It is unknown how exactly Skyrise died. The Avatar found her body in Ultima VII/2 on the northern of the Isles of the Mad Mage in some ruins. Pulling a lever to cause the lava to engulf the body, Skyrise was reborn.

She was surprised that the Avatar asked for her real name, as she'd mostly just been addressed as "phoenix". She then went on to tell the Avatar about her people and how they were drawn to places where the balance had been disturbed. She continued, that with her now alive, balance could be restored to Serpent Isle.

She then gave the Avatar one of her eggs to thank him/her. Exactly what he/she needed for Erstam to exchange it for his Serpent Jawbone.