Jean Grey is one of the original X-Men and one of the most powerful beings in comics. Unfortunately, she’s also become somewhat of a punchline due to her penchant for perishing and then being resurrected with a frequency that stands out even in the world of Marvel Comics, where characters have a habit of returning to life. The amount of times Jean Grey has been taken out is truly preposterous - as is the amount of times she's come back to life, which is somehow slightly higher.
Following her debut alongside her teammates in X-Men #1, Jean Grey undergoes a number of transformations. First going by names like Marvel Girl and Ms. Psyche, it's not until she becomes the Phoenix that she discovers her hidden potential. On the one hand, the Phoenix Force empowers Jean like few others in the history of the Marvel Universe; on the other hand, it dooms her to a seemingly endless cycle of resurrection, much like the mythical creature that inspired the moniker.
Jean Grey, along with the other four original X-Men, makes her Marvel Comics debut in 1963’s X-Men #1 by Jack Kirby and Stan Lee. Unlike most of Lee and Kirby’s co-creations, Grey and her fellow mutants struggled to find their footing with the readership. This initially led to a handful of cancellations and hiatuses for the comic before it relaunched as the All-New, All-Different X-Men - and established the team as a mainstay in the Marvel Universe.
The comic's irregular publishing schedule contributed to the delayed introduction of Jean’s trademark attribute - her propensity for being resurrected a seemingly endless amount of times - by more than a decade. Since then, however, it’s been a nonstop cascade of demises and rebirths for Jean Grey.
In 1976’s X-Men #101, Jean Grey experiences her first brush with mortality in the form of a bold sacrifice. During a space mission to bring a shuttle back to Earth, the X-Men and their would-be rescuees find themselves on the verge of a short and fiery reentry.
Against Scott Summers’s protests, Grey uses her prodigious telekinetic abilities to safely pilot the shuttle back to Earth while everyone else remains inside the vessel’s shielded interior. Unprotected by the shielding, Grey absorbs a dangerous amount of radiation into her body. That alone would be enough to immolate her, but then the shuttle plummets into Long Island’s Jamaica Bay - and seemingly seals her fate.
Fortunately, the X-Men don’t have to mourn their teammate's loss for very long.
After appearing to perish in a shuttle disaster, Jean Grey immediately rises from the waters of Jamaica Bay... or, at the very least, something resembling Jean Grey rises.
Now calling herself the Phoenix and claiming to have been saved by the cosmic Phoenix Force (which had established a connection with her on a previous space mission), Grey returns to active duty with the X-Men. However, it soon becomes clear she’s been irrevocably changed by the experience.
After resuming her relationship with Scott Summers and her friendship with the rest of Marvel’s merry mutants, Grey appears to be no worse for the wear. But there’s a darker truth hiding below the surface. Her encounter with the Phoenix Force results in a major boost to both her telepathy and her telekinesis - and a sharp reduction in her self-control and overall grasp on humanity.
Due to the manipulations of Mastermind and the Hellfire Club, Jean Grey becomes corrupted, transforming from Phoenix into Dark Phoenix. Throughout the duration of the seminal "Dark Phoenix Saga," Grey grows more and more powerful, and slips further and further into villainy, until she’s flying around space consuming entire civilizations with no apparent remorse.
The Dark Phoenix clashes with her former teammates, but they are unable to break through to her old personality - and unable to bring themselves to end her. It takes the intervention of Charles Xavier himself - and an epic bout of psychic combat - to bring Jean Grey back to relative normality. But the reprieve is short-lived.