Firebird

The Firebird is a major character from the Disney movie Fantasia 2000. The Firebird serves as the main antagonist in the film's final segment The Firebird Suite. His scene obviously represents death and destruction.

He is first seen inside a mountain(more likely a volcano since nothing grows near the mountain), where the segment's protagonist, the Spring Sprite, inadvertantly wakes him up. This makes him so mad that he chases after her. As he does, he burns the forest she had worked so hard on growing until finally, he catches her. However, she is revived by the Elk. It is unknown what happened to the Firebird after that, although it is suggested that he comes every time a volcano erupts. Volcanoes can due serious damage to an ecosystem, but the ecosystems are known to heal in time.

A similar real life example is the Mount St. Helen's 1980 eruption. Mount St. Helen's is located near a lush national park and when it erupted, much of the forest was destroyed. Many doubted the land would ever heal, but much to everyone's surprise, the area is healing, just as everything is healed in the segment.

Role in Ultima
In Ultima, Maleficent managed to summon the Firebird and take control over it so it wouldn't go berserk on the Organization. She understood the Phoenix was very powerful, so she drained some of its power to make it obedient to her. It has currently been given intelligence so that it could be a part of the Demon Lord council.