The X-Men and the Avengers are two of the most prominent superhero teams in Marvel Comics, and in some cases, members of these respective groups cross over into the other. While it’s rare to see a non-mutant superhero joining the X-Men in an official capacity (though the recent induction of the Juggernaut proves it isn’t impossible) there are many instances in which an X-Men member will join the Avengers.

The Avengers is simply a team of Earth’s Mightiest Heroes, meaning there is no set roster like, for instance, the Fantastic Four. To be a member, one simply has to possess some kind of super-human enhancement (whether that be technological, biological, or supernatural), and they must have a desire to protect the world - and sometimes the universe - against threats none of them could handle on their own. Therefore, it’s a given that a number of X-Men would be recruited on the Avengers, as they’ve been trained since childhood by Charles Xavier how to use their powers for the good of humanity. That being said, not all X-Men/Avengers members are measured the same, as some are undeniably stronger than others. Here are the 10 most powerful X-Men heroes recruited to join the Avengers, ranked.

10 Wolverine

Wolverine joined the Avengers in New Avengers #6 by Brian Michael Bendis and David Finch, and while many fans might think of Wolverine as one of the most overpowered mutants in Marvel Comics, that’s not necessarily true. Wolverine might have a healing factor and nearly indestructible metal claws, but in terms of sheer power, he’s nowhere close to the level exhibited by the other entries on this list. In fact, Wolverine is classified as a beta-level mutant by the current X-Men classifications of mutant power-scaling. Sure, he’s fantastic for the more covert missions carried out by the Avengers (with Secret War being a prime example), but his effectiveness against cosmic threats is minimal on a team filled with heroes on-par with the likes of Captain Marvel and Thor.

9 Beast

Wolverine might be a more ferocious presence on the battlefield than Beast, but it’s fair to say that Beast brings a similar level of ferocity during a fight, with the added benefit of having genius-level intellect, making his overall contribution to the Avengers that much more useful. In fact, in Wolverine #31 by Benjamin Percy and Leinil Francis Yu, Beast creates multiple clones of Wolverine, which only proves how much more Beast has to offer the Avengers than Wolverine does. Though despite the direct comparison between Wolverine and Beast justifying their respective placements on this list, Beast was a great addition to the Avengers since his inclusion on the team in Avengers #151 in his own right, though he’s far from the most powerful.

8 Cannonball

Cannonball was a member of the New Mutants before joining the more hardcore X-Men affiliated team X-Force, and wouldn’t join the Avengers until Avengers Vol. 5 #2 by Jonathan Hickman and Jerome Opeña. Cannonball is much more explosive than the previous two entries on this list, and his power level is more in-line with the cosmic-level threats the Avengers are regularly dealing with. In fact, in Uncanny X-Men #341, Cannonball beat Gladiator in a one-on-one battle that pushed his powers to their absolute limit. As seen in the classic Phoenix Saga, Gladiator and the Shi’ar warriors he commands outclass the X-Men immensely (including and especially the likes of Beast and Wolverine), making Cannonball the first real contender on this list in terms of sheer power.

7 Sunspot

Sunspot joined the Avengers the same time Cannonball did in Avengers Vol. 5 #2, and his background with the X-Men (and their affiliated teams) is nearly identical to Cannonball’s as well. The difference, however, is their power level. Sunspot has the ability to absorb solar radiation and transfer that energy within his own body, turning it into strength. For instance, Sunspot once got strong enough to one-shot the Hulk while emitting vast amounts of raw energy he was previously able to absorb. Not only that, but he can gain sustenance from solar radiation, allowing him to live without the need for food, water, or even oxygen, making him not just incredibly powerful in battle, but also a great asset for the Avengers on any given mission in space.

6 Havok

Like Sunspot, Havok was able to beat the Hulk in a fight, doing so with a single blast of his concussive energy (as shown in Incredible Hulk #150). So, when Havok finally joined the Avengers in Uncanny Avengers #1 by Rick Remender and John Cassaday, the previously established ranks of Earth’s Mightiest Heroes knew they were getting a proven heavy-hitter on their team. Not only that, but Havok was chosen to be the leader of the new team of Avengers in that very issue, as Captain America hoped he could help bridge the divide between the Avengers and the X-Men following their conflict. Havok is arguably stronger than perhaps the strongest member of the original Avengers while also proving to be an integral part of the team’s future.

5 Rogue

Rogue can go toe-to-toe with anyone due to her mutation. Not only did Rogue take down Captain Marvel with a mere touch, but she then used Carol Danvers’ powers to break into the Avengers compound and bring the team to their knees practically solo. This happened in Avengers Annual #10, and was Rogue’s breakout role as one of the more formidable earthbound villains in Marvel Comics at that time. Before long, however, Rogue would use her immense and nearly unlimited power for good with the X-Men. Then, in Uncanny Avengers #4 by Rick Remender and John Cassaday, Rogue joined the very team Havok had been chosen to lead, making her an official Avenger - and one of the team’s strongest recruits to date.

4 Dazzler

Dazzler might be one of the most underrated comic book heroes of all time, given how understated her powers were upon her debut. Dazzler can turn sound waves into light waves, and can manipulate those light waves across its entire spectrum. When she was first introduced, she was a pop star who turned the sound of her own voice into a spectacular light show. However, she could have also turned that sound into immensely powerful photon blasts, effectively putting her on-par with the likes of Captain Marvel. This made Dazzler perfect to join the ranks of the all-female Avengers team known as A-Force (as shown in A-Force #2 by Kelly Thompson, G. Willow Wilson, and Jorge Molina). What makes Dazzler a standout on this list above other entries with similar powers is her designation as an alpha-level mutant, along with the fact that the application of her powers are limitless. Indeed, she once absorbed the sound of Black Bolt’s voice, and even took down the Hulk with relative ease.

3 Sunfire

Another alpha-level mutant, Sunfire has the power to absorb solar radiation and can generate superheated plasma in ways that makes the level of power he can unleash akin to that of an exploding star. For instance, when the Annihilation Wave returned in X-Men #2 by Gerry Duggan and Pepe Larraz, Sunfire wiped it out in its entirety all by himself. That’s a level of power that almost no one in the Marvel Universe can match, save for literal cosmic gods. This exhibition of raw power alone made Sunfire the perfect Avengers recruit when he joined the team in Uncanny Avengers #5 by Rick Remender and Olivier Coipel.

2 Storm

The first omega-level mutant on this list, Storm’s nearly unparalleled power speaks for itself. With her mutant ability to control the weather, Storm can effectively alter the lives of every living organism on a planetary scale. Storm had been using these abilities to battle increasingly deadly foes while on the X-Men, but finally used them as an official member of Earth’s Mightiest Heroes in Avengers Vol. 4 #19 by Brian Michael Bendis and Daniel Acuna, only eventually leaving the team to join with her fellow mutants during the Avengers vs X-Men event - something which made Iron Man admit that Storm was the best Avenger the team ever lost.

1 Quentin Quire

While perhaps not the most well-known X-Man-turned-Avenger on this list, Quentin Quire aka Kid Omega is easily the most powerful. Not only is Quentin an omega-level mutant like Storm, but his omega status stems from his unmatched power as a telepath. Plus, Quentin is an incredibly skilled telekinetic, and has been described as a ‘Psionic of the Highest Order’. Quire’s psionic abilities effectively make him a powerhouse akin to Green Lantern (but without the need of a ring), which was proven true when he created a rocket launcher from pure psionic energy. While that’s impressive, it’s only the tip of the iceberg of what Quentin is capable of, as his powers can arguably rewrite the reality of those he uses them against without Quire breaking a sweat - that’s how strong his omega-level telepathy is. Therefore, when he joined the West Coast Avengers in West Coast Avengers Vol. 3 #1 by Kelly Thompson and Stefano Caselli, the Avengers officially gained the strongest mutant recruit they’ve ever inducted.

While some of these mutant-heroes are stronger than others in terms of raw, unadulterated power best suited to handle Avengers-level threats on a cosmic scale, each one of these 10 X-Men definitively proved themselves to be worthy to join the ranks of Earth’s Mightiest Heroes.