In the late '00s, early '10s things were pretty bad for mutants. Scarlet Witch had reduced the race to a small fraction of their former numbers and Norman Osborn and his Dark Avengers were breathing down the necks of the ones remaining. Osborn would form his own team of Dark X-Men, which would bring Namor into the mix.

Namor, Marvel's first mutant, would jump ship and join up with the X-Men, staying with the team throughout the Utopia era of the team until Phoenix Force came and upended everything for everyone. He added a lot of power and prestige to the team but also a lot of baggage. Let's look at all the ways he could be an asset... as well as how he was detrimental to the team.

10 Good X-Men: Legitimacy

namor on his throne

Namor is the king of Atlantis and a leader on the world stage. While he hasn't always had the best relationship with the powers of the surface world, his place as a world leader gives him an air of legitimacy and that air was passed onto the X-Men as well.

This was definitely something they needed as they had just defied Norman Osborn, one of the most powerful men in the country, and sorely needed someone powerful in their corner. Namor provided that.

9 Bad X-Men: His Relationship With World Leaders

Namor used to attack the surface world. A lot. It's kind of his thing. He was an enemy of the Golden Age Human Torch, helped during WWII, and then lost his memory. He would regain his memory and take up his crusade against the surface world again, going back forth between being an ally of the world's heroes and an enemy.

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While he granted mutants legitimacy on the world stage, he also brought all of his baggage with him and that wasn't always the best thing.

8 Good X-Men: Experience

Namor has been fighting heroes and villains since before World War II started. This instantly made him one of the most experienced X-Men on the team, second only to Wolverine. This experience would pay off well in his time with the team.

This was a very hard time for mutants and they needed people with experience facing adversity and Namor has that in spades. He was used to fighting against not just the worst of threats but also against the heroes themselves, which would help in what was to come.

7 Bad X-Men: Arrogant

One of Namor's biggest problems in general is how highly he thinks of himself. Now, it's not that he doesn't have reasons to be arrogant- he's the king of the vastest kingdom on the face of Earth, one of the most powerful men around, and immensely strong and durable, able to go up against the toughest heroes and villains.

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However, his attitude can be a major turn off when dealing with others, especially in a team situation. It's always been the biggest challenge facing people who work with Namor.

6 Good X-Men: Searebro

When Jean Grey returned to life, she found herself immediately up against Cassandra Nova and her manipulation of the general public. Nova was able to frame Jean for the death of a Congressperson she was possessing and Jean and her team needed a place to hide.

Namor gave it to them in the form of Searebro, a place where Jean's team of X-Men could hide from Nova and plan their next moves. Without him, Nova easily would have been able to take Jean and her team down.

5 Bad X-Men: How He Joined The Team

At the time he joined, Namor was part of Norman Osborn's Cabal and a member of his Dark X-Men team. Emma Frost would convince him to jump ship with her, but it still was a very bad first impression, one that wouldn't ingratiate any of the mutants to him right away.

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At first, no one was sure whether they could trust them. He had betrayed someone to help the team, but what would stop him from betraying this team? He would eventually earn his place, but he began his time with the team as someone few trusted.

4 Good X-Men: He Committed Himself To The Cause

Namor the Sub-Mariner stands with the X-Men Cyclops and Emma Frost

Surprisingly enough, Namor actually wholeheartedly embraced being an X-Man and a mutant during his time with the team. It's especially weird when one realizes that Namor really didn't even need to. While mutants themselves were facing extinction and persecution like they never had before, none of that would have affected Namor in the slightest.

Namor could have just as easily stayed underwater and never had to deal with any of the problems that mutants were having but he came up and helped out, showing a selflessness he rarely if ever showed.

3 Bad X-Men: His Prior Relationship With Emma Frost

Namor kind of has a thing for blonde women with significant others. His crush on Invisible Woman started a rivalry with Reed Richards and the Fantastic Four that has lasted for years and during his time as a Dark X-Man, it was revealed that in the past he and Emma had a tryst as well.

Namor being Namor, he wasn't one to let things be water under the bridge and liked to occasionally rub it in Cyclops's face that he and Emma had been together and occasionally make new passes at her, which are both pretty scummy moves.

2 Good X-Men: A Big Time Powerhouse

Namor is one of the toughest people on the planet. For years, he's been facing down the Avengers, Fantastic Four, the Hulk, and all kinds of villains and was able to not only walk out of those fights but also win them. That says a lot about just how formidable he is and the X-Men needed that kind of muscle when he joined the team.

It's impossible to deny that Namor became one of the toughest X-Men immediately upon joining the team, adding a level of power and expertise that few had.

1 Bad X-Men: Headstrong

Besides being arrogant, Namor's biggest problem is he's headstrong. When one is a monarch of their own country, they get used to doing whatever they want so it does make sense that Namor would be that way. However, it doesn't always work out very well in a team environment, especially one in the situation the X-Men were in at the time.

There were several times when Namor's headstrong nature came back to bite Cyclops and the team. When a team is in as dire straits as the X-Men were, someone as headstrong as Namor can be a big problem.

NEXT: Namor Vs Aquaman: Who Really Is The Stronger Hero?