Audiences and fans alike have noticed plenty of similarities between Marvel Comics' Captain Marvel and DC Comics' Superman. It's not hard to see why, as both characters rank among the most powerful members of their teams. By that sentiment alone, characters like Hyperion, Ikaris, and Sentry are equally deserving of being Marvel's undisputed version of Superman. However, what separates Captain Marvel from the rest and what makes her most deserving of being Marvel's Superman is how she dies at the end of Captain Marvel: The End.
The ending of The End echoes something similar that happens to DC Comics' Superman in Grant Morrison and Frank Quitely's All-Star Superman, a story where the title character is slowly dying thanks to overexposure to his biggest source of power, the sun. The series is iconic, with some fans even thinking Superman's All-Star costume should be his main look. Even more ironic is the ending where Superman's "death" sees him become a solar being, living inside of the sun to repair the damage created by Lex Luthor. While he doesn't succumb to his illness or die outright, Superman's absence from Earth after a year is considered a death in the eyes of its citizens, save for Lois Lane.
In a similar vein is Captain Marvel: The End, written by Kelly Thompson and with art from Carmen Carnero. The one-shot takes place in 2051 during a post-apocalyptic Earth, with only a slew of familiar heroes surviving alongside new ones. Here, Captain Marvel returns to discover the sun is dying, putting whatever's left of the planet in peril. Without hesitation, Carol leaps into space, reigniting the sun and saving the planet at the cost of her life. As their respective company's most theoretically overpowered characters, the two have always sparked comparisons to each other from audiences. Captain Marvel and Superman even share a weakness to magic. In some cases, those comparisons are made deliberate in their respective comics. However, in comparing Captain Marvel: The End with All-Star Superman, those comparisons are obvious.
The most obvious similarity is that both heroes meet their fates at the hands of the sun in the conclusions of their respective stories. That connection reads even deeper as both characters use their final ounce of strength to nourish life. That's what both All-Star and The End are ultimately about, finding a greater appreciation for life. These themes are explored through the gaze of Superman and Captain Marvel, two typically overpowered characters who find themselves in rare instances of vulnerability. It's been stated that both characters are overpowered, but both stories touch on how neither can save everyone on the planet by themselves. More than just other people needing them though, Superman and Captain Marvel need others too. Most notably in Morrison and Quitely's All-Star Superman #4, where Jimmy Olson stops a rampaging Superman infected by Black Kryptonite.
Though both characters are ultra-powerful, their endings reframe them as heroes whose ultimate strength is their compassion and ability to connect with others. Certainly, characters like Hyperion or Ikaris might fit the moniker of "Marvel's Superman" better on paper, but they're missing this essential element. The similarities have always been there, but it took Captain Marvel's death to finally confirm she's Marvel's Superman.