They are very good friends. In Action Comics 1028, Superman revealed that when he seeks guidance he often goes to Martian Manhunter before consulting with other heroes. Why didn't DC did a Martian Manhunter movie yet? The character seems to be fairly known and has such an interesting set of powers.
For alternate versions of Martian Manhunter, see Martian Manhunter's character hub. J'onn J'onzz, known by some as the Martian Manhunter, is an alien from Mars that eventually traveled to Earth and posed as a Lieutenant General named Calvin Swanwick in the United States Army, and later as Secretary of Defense.
Did Superman know the general was Martian Manhunter?
Felt like watching Man of Steel again. During the film, it didn't seem like Superman acted differently with Swanwick, however towards the end when crashing the drone in front of his car, Superman's choice of words could be seen as hinting that he knew.
Although obviously alien in appearance, the form that most Earthlings associated with the Martian Manhunter is not actually his true form. In his natural state of being, J'onn has a slender body, with sharp, angular features and a tapered cranium.
At the beginning of Grant Morrison and J.G. Jones' Final Crisis, Martian Manhunter was killed off for the first time. This happened when the longtime Justice League hero was captured by the villainous Libra, who brought the injured martian as a gift to the Human Flame, a member of J'onn J'onnz' rogues gallery.
Martian Manhunter is faster, more agile and has more powers than even Superman. However, in terms of strength alone, natural strength that is, Superman takes it. While J'onn is able to outmatch Shazam, that doesn't make him a match here for Superman.
Why is Superman afraid to fight Martian Manhunter?
Superman considers Martian Manhunter the most powerful being in the universe, and admits he would be scared to face him in battle. Despite Superman's own remarkable abilities, he recognizes and respects Martian Manhunter's strength and versatility.
Being in such high levels of power and influence within the government, it seems as though Martian Manhunter seemed content to play at being a human while doing good when he could behind the scenes, presumably not wanting to risk being exposed as an alien life form from Mars.
In its best-known form, it is a green, crystalline material originating from Superman's home world of Krypton that emits a unique, poisonous radiation that can weaken and even kill Kryptonians.
Why is Martian Manhunter so weak in Justice League?
Despite his great power, which often rivals Superman, Martian Manhunter has a most common weakness: fire. This fear is the result of manipulation of the Martians by the Guardians of the Universe in the distant past; the Martians were once composed of fire - they used it to reproduce.
In The New 52, the weakness to fire is pyrophobia that is unique to him as a crippling anxiety, due to the trauma of witnessing the fiery death of his race, an explanation previously established in the 1988 Martian Manhunter miniseries.
Naturally, Superman fears death like most people, but his battle with Doomsday is especially traumatic when considering his powers. Superman is nearly invulnerable to physical attacks, so having had a being beat and stab him to death is even more unnerving, despite Superman's eventual resurrection.
While Superman himself does not pose a threat, his existence does. Bruce fears Superman because he feels he will bring danger to the planet, which he does albeit indirectly. Zod is responsible for the destruction of Metropolis, but he never would have thought to come to Earth if not for Kal-El.
Superman's greatest fear is becoming his own worst enemy and failing to uphold the standards set by himself in protecting humanity. As seen in the 15 Times Superman Killed His Enemies , he has to face this fear in the saddest of outcomes.
His only weakness in an inherent fear of fire, which all Martians have. All of these abilities make him one of the most powerful beings on the planet. But it is his brilliant mind and steady leadership style, along with his gentle soul, that have made him a beloved member of the League in all of its incarnations.
Batman was deprived of his parent's love early on in life, so he's jealous that Superman grew up with love and affection from his Earth parents. Superman has incredible abilities, so he's jealous that Batman became the superhero he is on his own merit despite not having the privileges of superpowers.
Superman's biggest fear is that, despite his immense power, he cannot save everyone who believes he will always be there to save them. Superman feels the pressure to meet the impossible expectation of being able to save everyone, even though he knows it is not possible.
Captain Atom has proven in past battles that he is stronger than Superman and has better fighting skills. He can also weaponize red sun radiation, which can weaken Superman like Kryptonite and magic. His sometimes uncontrolled nature has earned him a reputation as one of the most dangerous DC heroes.
In short, in a straight-up battle, Dr. Manhattan could easily destroy Superman. All he would have to do is disintegrate him and no matter how powerful Superman might be compared to other beings, Dr. Manhattan is simply too powerful.
Nevertheless, these weaknesses are difficult to come by, and Superman's seemingly boundless physical strength and years of experience hands-down make him the strongest member of the Justice League.
