When the cosmic force known as the Phoenix Force returned to Earth, it staged a contest to determine its next host, and Echo was one of many individuals summoned to the White Hot Room for it. The Phoenix empowered the assembled champions and had them fight each other in trials by combat. In one of the earliest bouts of the tournament, Echo was pitted against Namor at the bottom of the Atlantic Ocean. Due to the favored battle conditions, Namor overpowered Echo and left her for dead in the ocean floor.
The Phoenix was drawn to Maya's suffering, as well as her ability to adapt and wield its power in different ways. It resurrected Echo and chose her as its host. During the final round of the tournament, Echo resurfaced from the bottom of the ocean and proceeded to intercept all the different fights taking place across the globe. Absorbing the portions of the Phoenix from each of the remaining contestants, Maya fully became the Phoenix. Afterward, she relocated to the Avengers Mountain so that the Avengers could study her new condition.
Echo one day found herself in a different universe and was an inmate at Ravencroft Institute. She chose not to escape. Instead, she used the powers of the Phoenix to keep Ravencroft's inmates in check. She was eventually approached by Blade the Vampire Hunter, who was also transported to that reality, and that reality's version of Captain America and told her that they planned to form the Avengers to restore reality to its proper place.
While Blade and Captain America recruited Black Panther, Echo recruited Thor, who had regained his powers and memories. With Wakanda helping find the Star Brand bearer Brandy Selby in the depths of space, the Avengers team was complete and confronted the Squadron Supreme when they came to Wakanda to investigate the Avengers.
Echo fought Power Princess but was unable to defeat her until she was aided by Brandy, and they used their combined power to knock Power Princess out. The duo then worked to destroy the source of the reality warp, President Coulson's Pandemonium Cube. With the Pandemonium Cube's destruction, reality was returned to normal, and Echo was returned to Earth-616.
On Avengers Mountain, Echo and Brandy passed every test they took, but Captain America was still hesitant about allowing them to join the Avengers. As Jennifer Walters (the Hulk) quit the team and dire sitations appeared, she accompanied the team on several occasions, officially joining after the attack of the Multiversal Masters of Evil.
