The Burning Acolyte

After stopping the Night Ghoul's attempt to steal a rare magical artifact lead to May Manerak; aka Acolyte, absorbing the energy of a large firey colored crystal, she thought that was the end of it. But time would show this to not be the case. As when the Daylight Defenders came against the terrifying entity of mystical fire; The Pheonix, it seemed to be their darkest hour. But as May pushed past her fear, and tried to take a stand against this menacing threat, she found herself suddenly engulfed in a strange new flame. This fire was completely painless, and in fact seemed to be rejuvenating her as well. Soon after, May finally emerged in a powerful new form, one that gave her near unmatched control over fire, highspeed flight, and even a newfound, intense and passionate confidence to face the goal ahead of her. It was then May Manerak became, 

The Burning Acolyte!

With this new and great power, she was able to stand up to against The Pheonix and bring this monster down. As she reverted back to her normal state, she had numerous questions: what was this new ability, what are its origins, and most of all; 

How exactly does she transform on command?