The Phoenix is a binary force; "Alpha-Omega. Chaos-Order. Beginning-End. Life-Death. Phoenix is the ion of creation. Dark Phoenix, the cold fire that brings it to its end."
The Phoenix Force typically works through hosts, although the reason is unclear; some have suggested it is because the Phoenix craves the emotional stimulus of living beings, and thus tries to fill a void within itself through its hosts. On two occasions, the Phoenix has been divided between multiple hosts - once forcibly, in the Avengers Vs. X-Men epic, and once willingly, as it sought a champion on Earth. But none of these individuals were true Phoenix hosts, for they did not find themselves bound to its essence, even if they did carry a burn on their very souls as a result of the experience.
Here are all the true Phoenix hosts - the ones who chose the Phoenix and were chosen in turn, who bound themselves to the will of the Phoenix and served its purpose, or else ascended to become one with it. These are some of the most powerful heroes in the history of Marvel Comics - and also some of the most dangerous beings in the universe.
The Demon Lords of Stasis
In Uncanny X-Men #13, the artificial intelligence named Unit told a tale of the first known Phoenix host - a billion years ago. He discovered a supernatural world whose ruler, a demon prince, had worked a great rite that paused evolution itself. The Phoenix Force - a cosmic force of change and evolution - objected to this, and chose a Messiah figure to restore evolution and sweep away the Demon Lords of Stasis. As Unit noted, there was a striking parallel between these events and Scarlet Witch's Decimation of the mutant race, with the emergence of a similar Phoenix-inspired "Mutant Messiah," Hope Summers.
Firehair
1,000,000 years before the present day, the Phoenix Force chose a human host for what seems to have been the first time - a woman who became known simply as Firehair, due to her red hair. Firehair was responsible for gathering together the Avengers of 1,000,000B.C., and she became Odin's lover. In a shocking twist, Marvel Comics has revealed this mysterious yet powerful figure is actually the mother of Thor - meaning he is actually the son of the Phoenix.
Feron, An Ancient Sorcerer
Feron was a sorcerer of another dimension who trained under his plane's Sorcerer Supreme, Necrom - along with his fellow mystic, Merlyn. They learned to travel the multiverse, but Necrom desired to go one further, and to gain power over the multiverse itself. Feron played a crucial role in Necrom's plan, bonding with the Phoenix Force in an attempt to create a multiversal singularity, and Necrom ultimately tore the Phoenix from its host - wounding both in the process, and harvesting a fragment of the Phoenix's energy to create the Anti-Phoenix.
Ohoyo Luak, The Phoenix of 1050 C.E.
Marvel's Phoenix Song: Echo miniseries has introduced Ohoyo Luak, the Phoenix host of 1050 C.E. She lived in Cahokia, in North America, and she understood the power of the Phoenix; as she told her time traveling Phoenix host descendant Echo, "You can bring whole civilizations to their knees! Change the course of the planets! Absorb the life force of the living and resurrect the dead!" Where many Phoenix hosts have attempted to restrain its power, she embraced it, and allowed it to show her the wonders of the universe.
A Forgotten Viking Phoenix Host
Mighty Thor #7 revealed an ancient adventure involving Thor, long before he had gained possession of Mjolnir. The issue revealed he wound up part of a team of heroes during those distant days, including a Viking woman who hosted the Phoenix, Chief Hellhawk the Ghost Rider, Nehanda the Black Panther, Bodolf the Black, an Atlantean princess who wielded the Iron Fist, and the Great Beast named Tanaraq. Their adventures have never been recounted, but it is possible this is the Phoenix host Thor took as a lover.
Rook'shir and the Blade of the Phoenix
An ancient Shi'ar named Rook'shir bonded with the Phoenix Force, and wreaked havoc across the entire Imperium. This rampage led to the formation of the first Imperial Guard, and their leader Gladiator successfully killed him. He left behind a legacy - a weapon called the Blade of the Phoenix, imbued with his power, that ultimately fell into the hands of one of his ancestors some 500 years after his death.
Fongji Wu, the Iron Fist who Wielded the Phoenix
The tale of Fongji Wu is told in New Avengers #25-27, a three-part story that tied in with the event. Fongji Wu was born in the city of K'un Lun, and visions of the coming Phoenix Force caused that city's leaders to train her to become one of the Iron Fists. When the Phoenix came, Fongji Wu became its host, and united with its purpose and will. She left Earth, never to return, and her fate is unknown. She did, however, leave one lasting legacy; because of Fonji Wu, the Phoenix Force will always have a vulnerability to the power of the Iron Fist.
Reno Phoenix, A Mysterious Host In The Wild West
In Jason Aaron's Avengers #50, Ka-Zar traveled through time and learned Earth had always had its defenders. One particularly intriguing partnership was in the Wild West, between Reno Phoenix and the Starbrand Kid. They have been long forgotten in the mists of time, and nothing is known about them.
Jean Grey
The most famous Phoenix host is, of course, Jean Grey - and her relationship with the Phoenix is a complicated one, subject to countless retcons. The Phoenix initially replaced Jean Grey, placing her within a restorative Phoenix Egg while it took her place, and it fell under the influence of Mastermind - ultimately going Dark Phoenix. But Jean has remained closely linked to the Phoenix ever since, so much so it's difficult to say where Jean Grey ends and the Phoenix begins. This was particularly true during Grant Morrison's New X-Men run, in which Morrison adopted the religious concept of "apotheosis" to explain the relationship between the two; in theological , a moment of apotheosis is one in which a human being transcends their humanity to become one with a pre-existent Divine. At the moment, Jean has rejected this, abandoning her link to the Phoenix, but that probably can't last.
Rachel Grey, Daughter of the Phoenix
The daughter of Cyclops and the Phoenix from an alternate timeline, Rachel Grey is one of the few Phoenix hosts not to succumb to the power of Dark Phoenix. Rachel claimed the power of the Phoenix when she first arrived in the main timeline, and she was Phoenix for years; although she was tempted, even using far too much power during a battle with Galactus, she always resisted the lure of the darkness. Sadly, Marvel seem to have forgotten Rachel Grey - with Jason Aaron's Avengers run even describing Thor as the Phoenix's only child.
