Marvel comics are filled to the brim with heroes and villains of varying powers and skills, and it's only practical that not everyone has appeared in the Marvel Cinematic Universe (MCU). Not only are there simply too many characters to cram into a single movie or phase, but their mere existence could've ended the epic war against Thanos a bit too easily. This would've made sense for comic fans, but it wouldn't be that cinematic for everyone else.
Still, it doesn't hurt to imagine what Avengers: Endgame would've been like if someone like Galactus or Lord Chaos - the literal embodiment of chaos in Marvel - came in to stop Thanos. Here are 10 heroes who are rumored to be coming to the MCU who could've changed the course of Infinity War and Endgame.
The Celestials
First seen in a flashback in Guardians of the Galaxy, the Celestials are some of the oldest and most powerful beings in all of Marvel comics. Literally referred to as "space gods" by many cosmic heroes, the Celestials are massive behemoths whose sheer size and power defy all known logic.
According to scientists, the Celestials can control Hyperspace, the source of all energy in the Marvel Universe. This makes them nigh-invulnerable and capable of doing anything, such as destroying planets in a heartbeat. Even Thanos with all of the Infinity Stones wouldn't stand a chance against them.
Adam Warlock
Ever since his confirmation in Guardians of the Galaxy Vol. 2, comic fans have been eagerly awaiting the day that Adam Warlock would grace the big screen. One of Marvel Comics' most powerful cosmic heroes, Adam's arch-nemesis is none other than Thanos himself.
Adam played a major role in the original Infinity saga, even wielding the Infinity Gauntlet at one point, but was ultimately cut out of the movies and saved for the third Guardians movie. Given his immense powers, his mere presence would've easily turned the tides in Endgame.
Nova
By inheriting the Nova Force once held by the alien Rhomann Dey, the normal teenager Richard Rider became Nova, the most powerful member of the Nova Corps. While the Nova Corps has already made its cinematic debut, Nova himself has yet to appear. If he did, things would've been a lot different in Endgame.
With his enhanced physiology, Nova basically wields the strength of the entire Nova Corps in his body. Having him join The Avengers either early on or as late as the well-timed Captain Marvel would've given Earth's forces a better chance against Thanos.
The Silver Surfer
Best known for being the harbinger of the living apocalypse that is Galactus, the Silver Surfer isn't just the most prominent Cosmic hero but he's also one of the most powerful. This is because he's imbued with the Power Cosmic itself, which basically makes him a demigod of sorts.
Following Marvel's reclamation of his rights, along with many others, and the MCU's pivot to the cosmic stories, his cinematic return is all but inevitable. With or without Galactus following his arrival, the Silver Surfer's presence in Endgame would've been enough to win the day.
The X-Men and Other Mutants
Ever since the confirmation that they'll appear in the MCU in the future, fans were desperately hoping for even the smallest tease of Marvel's famous mutants in Endgame. If they fought alongside the Avengers, the war against Thanos' forces would've been a lot more even.
Unlike most of the current MCU heroes, the mutants have uniquely biological superpowers, instead of ones created by science and ingenuity. From Professor X's mind control to Magneto's mastery of magnetism to the Phoenix Force that resides in Jean Grey, the mutants' powers would've been a massive game-changer.
Mephisto
Ever since Dr. Strange confirmed the existence of ethereal planes in the MCU, fans have been hoping that Mephisto - Marvel's version of Lucifer - would appear. An anti-hero on his best days, Mephisto is a literal silver-tongued devil who can convince anyone to do his bidding.
As if his hellish powers weren't enough, his words would've been more than sufficient to bring Thanos to his knees. Mephisto also played a major role in the original Infinity Gauntlet, acting as Thanos' devious advisor who wanted the Stones for himself. Also, Al Pacino wants to portray him.
Lady Death
Like Mephisto, the absence of Thanos' love interest Lady Death in the MCU disappointed some Infinity Gauntlet purists. The literal embodiment of mortality's end in the Marvel Universe may not be interested in Thanos, but her powers and aura are enough to turn the tables.
This isn't just because Lady Death can kill anyone by just breathing in the same space as they do, but because Thanos would literally do anything for her affection. With just a glance, she could've made Thanos stop or commit even worse atrocities, if she wanted to.
Deadpool
He may be the most successful hero in Fox’s former Marvel line-up, but the Merc With A Mouth’s future in the MCU is still a mystery. If the rights to Deadpool were cleared up earlier, his contribution in the war against Thanos wouldn’t just mean the addition of his signature fourth-wall breaking jokes but Thanos' personal vendetta against him.
You see, Lady Death chose Deadpool over Thanos. Their strange love triangle would’ve tonally clashed with Infinity War and Endgame but let’s face it – watching Ryan Reynolds bicker with Josh Brolin again would be worth the price of admission.
Dr. Doom
It's only a matter of time before Dr. Doom, the proud dictator of Latveria, enters the MCU. With superior scientific and magical knowledge at his fingertips, Marvel's most iconic villain could've easily gone one-on-one against the Mad Titan himself.
Though he may be a normal man in a suit of armor, Dr. Doom is a fast learner who mastered cosmic powers and intellect through sheer force of will. Most famously, he bested the Beyonder during Secret Wars and absorbed that godlike entity's powers... right after stealing Galactus' powers to do so.
Squirrel Girl
She may look like a joke character, but Squirrel Girl is actually one of the most powerful Marvel heroes in active service. Not only are her official stats on par with The Living Tribunal, but canonically she defeated Thanos.
As the MCU takes more risks in its upcoming slate, audiences may live to see the day when Squirrel Girl - who's also a favorite among fans - appears on the big screen. If she did show up in the earlier movies, she would've defeated Thanos just as she did in the comics: off-screen and with ease, much to her own surprise.