WARNING: The following contains spoilers for Avengers #40, by Jason Aaron, Javier Garrón, David Curiel and VC's Cory Petit, on sale now.
The Phoenix Force has a long history of bonding itself to mutant hosts on Earth to channel its fiery potential as an entity that can bring about cataclysmic destruction and miraculous rebirth. While the cosmic entity is usually known for associating with the X-Men, the Phoenix Force has recently been playing a prominent role in the Avengers' latest adventures following the team's recent showdown with the Ancient Egyptian God of Vengeance Khonshu.
And as Earth's Mightiest Heroes track down the Phoenix Force to the Savage Land in Avengers #40, one of their own becomes the entity's surprise new host: Captain America.
After leaving its previous host Moon Knight, the Phoenix Force mysteriously remained on Earth, recuperating inside of a volcano on a remote island. As the Avengers approach to investigate and potentially contain the destructive entity, they are attacked by Namor leading his own rival team of aquatic heroes, the Defenders of the Deep. The resulting fracas awakens the Phoenix Force from its slumber, and it flies to the Savage Land where it's intercepted by Doctor Doom who manages to absorb a fraction of its cosmic power for himself, with the megalomaniacal supervillain gaining a fiery appearance to match.
As Doom desperately moves to gain the entirety of the Phoenix Force for himself, the entity seeks to bond to a host who can challenge him. With Captain America as the closest Avenger on the scene, the Sentinel of Liberty absorbs the remainder of the Phoenix Force to oppose the empowered Doom, taking on a radical transformation himself. Fighting to standstill, Doom notices that the Phoenix Force will keep Steve Rogers alive and in the fight no matter what the villain inflicts on him.
Realizing that any attempt to wrest full control of the cosmic entity from Captain America will be fruitless, Doom opts to forfeit the two's fiery battle while Steve himself is whisked away into a strange realm where several current and former Avengers and other Marvel heroes and villains have apparently been drafted into a tournament to decide who will wield the Phoenix Force.
Historically, the Phoenix Force has bonded to mutants, most notably Jean Grey after being drawn to her latent telepathic abilities that were awakened after encountering a solar flare during a mission in deep space. During Avengers vs. X-Men, the Phoenix Force was divided between five different hosts, dubbed the Phoenix Five, who set out to reshape the world in their image. Among this quintet was Namor, who quickly formed a rivalry with Black Panther and has craved a return to that level of omnipotent power after first gaining a taste of it during the 2012 crossover event, fueling his renewed animosity towards the Avengers as the Phoenix Force returned to Earth.
While the heroes' current state is still a cosmic mystery, the Phoenix Force appears to have set its sights on Earth's Mightiest Heroes and their allies. T'Challa is poised to have his own turn bonded to the fiery entity, revealed by advance solicitation information and the cover to an upcoming issue, which suggests that several of the Avengers will each have a taste of the Phoenix's power as the tournament commences. Considering that the Phoenix Force has steered heroic characters like Jean Grey, Cyclops and Namor into decidedly villainous actions before, the Phoenix's next host may need the emotional fortitude of Captain America to keep themselves from becoming a Dark Phoenix.