John is a young African-American man, with brown eyes and short black hair. He is tall with a very athletic physique. As a detective he usually wears a black suit with a white shirt and a tie. He also wears his badge on his belt.
As a Green Lantern, John wears a sleek energy constructed costume, created by his power ring, which is a necessary accessory. Like all Green Lanterns' costumes its colors are green and black. He is wearing a black tight suit, which covers all of his body except from his hands, neck and face, underneath the energy contracted green details of his costume, which includes bracelets, boots and the Green Lantern's emblem on his chest, which expands into a small armor covering his chest and shoulders. While in costume his eyes also glow green.
John is shown to be rather serious about his job. He is very loyal to his job but seems doubtful about his purpose, which is something that Parallax was able to utilize against him. He is also full of regrets over the loss of his friends and the majority of the Green Lantern Corps.
In New York, detective John Stewart among a few other police officers is chasing a criminal into an abandoned alley. As the thug begins to fire on John, the Green Lantern ring creates a bubble to protect him, which then allows John to create a Green Lantern fist which he then proceeds to use to knock the perp into the cop car in front of the baffled police officers who wondered what just happened. As John proceeds to walk away, his fellow Lantern teammate Salaak proceeds to contact him to let him that there is a new recruit in need of orientation and adjusting on Earth. John questions the decision of having another human as a member of the Corps which Salaak mysteriously says "who said he was human?"
Later in Metropolis, Superman begins to apologize for the mess he caused, as he flies off in order to figure out how to properly control his power ring. As he does he flies into John Stewart who tells Clark they need to talk.
At Watchtower, John tells Clark that the rings are powered by the willpower of their wearers which is why they choose people like himself, Kyle Rayner and Hal Jordan as Corps members. Lois Lane and Tess Mercer disbelieve that John has a stronger will than them or any other of the 6 billion people on Earth, with Tess even wondering how did someone like Alan Scott get hold of one of their rings, with John admitting he doesn't know what loophole Alan used to get a ring of his own. Clark then questions what gives a Guardian or whoever is left the right to force other sentient beings into service. John says it doesn't matter, orders are orders and Superman is a soldier now.
In the Fortress of Solitude, Clark tries to control the functions of his power ring but he finds it very difficult. John Stewart, not being able to answer his questions, tells him to be patient, trust the Corps, as it is, like the Guardians, older even from Earth, as well as not question the rules. But Clark gets frustrated on carrying a weapon so powerful, without knowing how to use it, so he decides to visit "the closest thing to an expert" he knows.
At S.T.A.R. Labs, John says he doesn't know a lot about his ring even though he wears it for a decade. Dr. Emil Hamilton explains that the ring enables the user to tap into power from beneath the fabric of reality and that the mind tells the ring how to filter and implement this power. Furthermore, the energy is traceable and acts as a locator. Suddenly, an employee of the lab says to Emil that a signal was detected similar to the one of the ring outside of the facility. John says he hasn't invite anyone from the Corps there, so he and Clark change back to their Lantern costumes and go to check what is going on. Much to their surprise they find an army of Manhunters waiting outside.
Superman and John Stewart try to contain the Manhunters' attack without putting in danger any civilian in Metropolis. Since they can not beat them, as their rings can't make a dent in them, Clark quickly decides to take the fight to a non populated area to avoid causing any casualties, so they fly to the Moon, where Justice League's new Watchtower base is still being built by S.T.A.R. Labs' drones. While fighting with them the two heroes hear the Manhunters saying that the Green Lanterns have violated a treaty, but Stewart says he has no idea what they're talking about. To aid Superman and Green Lantern in their battle, Tess takes under her control the drones and commands them to attack the Manhunters. During the battle, John realizes that the Manhunters are powered by yellow rings and that is why their rings can not work on them so he tells to Clark to fall back. Superman tells to Tess to stand down and then ends the battle with a powerful blast of heat vision destroying the remaining Manhunters. Clark asks John if this is the last of them and he says there's always more.
On the Moon, a group of Green Lanterns explain to Clark and John that there is no treaty between the Guardians and the Manhunters, as well as one of them suggests that these Manhunters were rogue units that have gone mad without a purpose. Superman asks who created the yellow rings that powered the robots and the Lanterns explain that in order to battle the Manhunters, the Guardians took extreme measures, as the rings powered by the emerald energy of will were not enough, so they created the yellow rings, that are powered by fear. Unfortunately, the yellow light also drew something from the darkness, the ancient fear entity Parallax. After this revelation, the Lanterns decide to return to their sectors and report to their post. Before leaving, Salaak, says something to John, requesting not to reveal it to the other Lanterns.
Travelling to an unknown part of the galaxy, John still cannot believe what Salaak has told him, but suddenly he and Superman come face to face with Parallax. The entity says that he could feel John's fear from miles away. The two Lanterns see that Parallax has imprisoned the presumed dead Guardians and feeds from them. Parallax says that they offered themselves to him as part of a trade, a treaty, their fear as eternal fuel for his hunger for the power they siphoned from his domain with the promise of never hunting him again. Clark tells Parallax that the terms of the treaty haven't been violated but Parallax says the Lanterns are gathering to destroy it, with Clark being the newest member of the Corps as proof of it. Threatening Clark, Parallax says that the Guardians have lost their luster and the Manhunters have failed so he seeks to feed from the population of Earth. He starts vomiting yellow rings and sends them through the universe to find recruits for his own Corps.
Parallax has captured Clark and John and says that his yellow rings have arrived on Earth, by now, as well as his "harvesters" will provide him with the fear of the humans, so he can feast on it. One of the imprisoned Guardians, Ganthet, communicates telepathically with the two Lanterns and informs them that the other Guardians are keeping Parallax distracted, so he can tell them that in order to defeat Parallax, they should find something the beast fears. He has more to say, but he's unfortunately cut off by Parallax, who promptly tears him in two. Clark says that Ganthet bought them some time, by distracting Parallax, and they need to fall back. They both create a cage around the asteroid Parallax resides, preventing him of leaving it. John then says that Clark must return to Earth to stop these yellow rings, because the more fear they generate the stronger Parallax will become but Clark doesn't want to leave him behind. John says that he doesn't have a choice and that he will buy Clark some time in order for him to get back on Earth, so Clark wishes John good luck and leaves but while he is leaving, Parallax manages to break though the cage he has been held in, ready to face John.
John engages in battle with Parallax while the entity continues to provoke him to give in to fear. Parallax taunts John about Hal Jordan's past deeds while under his control, like the deaths of two other human Green Lanterns, as well as says that he can bring them back. Moments before overtaking him, Parallax tells Stewart he's been deceived by the Guardians, that he should let all of that go and embrace his fear.
In Gotham, Superman, Batman and Nightwing battle the en-powered patients of Arkham but suddenly all the Yellow Lanterns stand still and kneel before him. Superman is surprised that the Lanterns surrendered so easily but he soon realizes that isn't the case. Parallax suddenly appears behind him, having John Stewart under his control.
Superman tries to convince John Stewart, who is possessed by Parallax, that it's okay to experience fear, that it's not an emotion anyone should repress or ignore. Superman's words about a soldier having the right to ask questions seem to have an impact on John, who briefly takes control of his body, but surprisingly Parallax gets back in charge and makes John respond by impaling Superman with a sword constructed by his yellow ring, saying the he is going to murder the whole world.
Parallax leaves John's body intending to take over Superman's but the Clark's teammates at the Watchtower succeed into resetting the rings. When they do all the Yellow Lanterns, including John, are released from the influence of fear and lose their powers with the rings turning black. Superman tells John, now he is free from Parallax, to get back up because they aren't done fighting yet.
The depowered John Stewart distracts Parallax, who insists earth has enough fear to feed him forever. Stewart lures the cosmic entity into a junkyard and smashes the left side of its head with a wrecking ball. Parallax is about to counterattack but the real help comes when the other Green Lanterns arrive on the scene with the entity of willpower. The two entities begin to battle and with an assist from Superman, they banish Parallax to its realm, which was his greatest fear.
In the aftermath, the Green Lanterns reevaluate their mission parameters and as their rings finish their reboot, they decide to choose their own destiny.
Later, Stewart explains to Clark that the Corps will endure and from now on no one will be conscripted against his will. John also tells Clark that his ring will be returned to the colony, where the Kryptonians will elect which of them will become the new Green Lantern of Sector 2813 and no one will know Kal-El was the ring's first choice.
During the battle with the Monitors, all the heroes are fighting valiantly. The powerhouses are stuck with their specific missions and none would be able to succeed and return to help Green Arrow and Speedy in time. Fortunately, out of nowhere, the cavalry arrives as Green Lanterns John Stewart and Aya shield the archer while Blue Lantern Saint Walker uses his ring to blast away their attackers. John reveals that all other space sectors are now erased and rebooting but with no time to relax they all race to help Wonder Woman.
Aya, John Stewart, Saint Walker, Supergirl and Superman continue to battle the Manhunters.
Aya asks John Stewart if this battle echoes the Parallax Wars as they battle powerful Monitor soldiers. John tells Aya this is far, far worse but the distraction is enough that Saint Walker is captured and killed, despite a delayed bombardment of emerald energy on the Monitor army. The two Green Lanterns are heartbroken as the blue ring leaves orbit for a new owner.
Superman spots a pod approaching Earth. The pod overcomes the heroes and speeds beyond them breaking the sound barrier, aiming itself at Watchtower. As it crushes, John and Aya protect everyone with an emerald bubble shield.
Later, John and Aya try to hold back the Omega Monitor and Aya calls John by his real name making him realize that they are at world's end.
The League stands in the Fortress standing judgment over the female Monitor. The universe is now back to normal though all that died is still dead. The female Monitor asks to die but J'onn points out that Clark would never kill anyone. The League then decides to send the Monitor to the Phantom Zone.
Three weeks later LexCorp holds a major press confrence and Lex introduces the public to a new monument built on the former Watchtower site. In a massive turnout Lex publicly admits that if it weren't for the heroes of earth the universe would be lost. Then Superman makes a speech that is broadcast all over the world. As the tarp falls away it reveals a stunning bronze statue of the Justice League.
- Bryan Q. Miller stated that unlike Bruce Wayne, John’s design was not based off any one particular actor. In a follow up tweet, he revealed that artist Cat Staggs based John’s likeness on cover after Phil Lamar on her covers, as a nod to the actor who voiced the character in the DC Animated Universe and Injustice games.
In the Comics
John Stewart is an architect and veteran U.S. Marine from Detroit, Michigan, who was selected by the Guardians as a backup Green Lantern to then-current Green Lantern Hal Jordan, after the previous backup, Guy Gardner, was seriously injured after getting hit by a car while trying to save a civilian. Although Jordan objected to the decision after seeing that Stewart had a belligerent attitude to authority figures, the Guardians stood by their decision, as well as chided Jordan for his supposed bigoted outlook on the issue. Jordan's opinion was that Stewart’s first mission began badly. His assignment was to protect a racist politician, and Stewart, while averting an accident, took advantage of the situation to embarrass Jordan in the process. When an assassin shoots at the politician, Stewart does not intervene with Jordan in response to the attack, which initially makes Stewart seem suspect. However, it turns out Stewart had good reasons for this apparent dereliction of duty because he was stopping a gunman from killing a police officer in the outside parking lot at the event while Jordan was pursuing a decoy. When Jordan confronts Stewart about his actions, Stewart explains that the politician had staged the attack for political advantage. Jordan then concludes that Stewart was an excellent recruit and has proven his worth.
For some time, Stewart occasionally filled in as Green Lantern when Jordan was unavailable, including some missions of the Justice League.
After Jordan gave up being Green Lantern in the 1980s, the Guardians selected Stewart for full-time duty. Stewart filled that role for some years, during which time he married Katma Tui, the Green Lantern of the planet Korugar who was initially assigned to train John in the use of his ring. Katma and John served together within the Green Lantern Corps of Earth alongside Hal Jordan, Arisia, Kilowog, Salaak, as well as other alien Green Lanterns.
After John’s ring was rendered powerless through the schemes of Sinestro and Katma Tui was murdered at the hands of the insane Star Sapphire, Stewart’s life began to unravel. First, he was falsely accused of killing Carol Ferris and then falsely accused of theft by South Nambia. Jailed and tortured in South Nambia for weeks, John freed himself with his old ring, now re-powered thanks to the efforts of Hal Jordan. In his escape, John inadvertently frees both a serial killer and a terrorist. When Jordan confronts John over his actions, the two friends come to blows until John realizes the “revolutionaries” he had been aiding intended to murder innocent civilians.
John finally forgave himself for his past mistakes and grew into a stronger, more complex hero when he became the caretaker of the "Mosaic World", a patchwork of communities from multiple planets that had been brought to Oa by an insane Guardian who had invaded John’s mind. Although bitter and sullen at his assignment at first, he overcame this and using his formidable intellect and talent for unconventional thinking, Stewart forged the Mosaic into a new society and eventually became the first mortal Guardian of the Universe, known as the Master Builder. As his reward for this new level of awareness, John was reunited with his late wife, Katma Tui. However, tragedy struck once again and Hal Jordan, possessed by Parallax, destroyed both the Guardians and the Central Power Battery, robbing John of his newfound powers and his resurrected wife.
With the return of Hal Jordan and the Guardians, the Corps in the middle east has been reorganized. Each sector of space now has two Green Lanterns assigned to it, and Stewart and Jordan now share regular duty for Earth’s sector, 2814. After the dissolution of the Justice League in the aftermath of the events depicted in the 2004 miniseries Identity Crisis, as well as the destruction of their Watchtower headquarters on the moon, Stewart has begun playing a larger role in metahuman affairs, working with many former Justice Leaguers.
During the events of Blackest Night, John visits the grave of planet Xanshi, thousands of black rings fly into the planetary debris, as well as reconstitute the entire planet. Xanshi itself then speaks to John, telling him "I can help you save them." Against his better judgment, John descends to the planet's surface. Once reaching the surface, John finds himself confronted by Katma Tui and the entire population of Xanshi as Black Lanterns. While battling them all, Katma tries to weaken John by claiming that he caused the planet's destruction. However, John, spurred on by Fatality's words, says that he wasn't the cause of it all and successfully fights off the Black Lanterns. After escaping Xanshi's atmosphere, John realizes that the planet is headed for Earth, along with every Black Lantern in the universe. He contacts Hal, warning him of the impending threat. Later, John is saved by combined efforts of the various Lanterns corps, who had just arrived to battle the Black Lanterns.
In the events of Brightest Day, John is seen on Oa, supervising the demolition of the buildings left in ruins after the Black Lanterns attack and planning the reconstruction. Suddenly, he is called to the Guardians' chamber, where they order him to join Alpha Lantern Boodikka in a mission to robot planet Grenda, Stel's homeworld, where the communications ceased abruptly without explanation and Lantern Stel and the population are missing. John agrees and departs with Boodikka.
Following the conclusion of the War of the Green Lanterns, John assists a new Green Lantern from Sector 282 'selected' during the period when Mogo was under Krona's control in adjusting to the power of her ring despite the possibility that she will not be allowed to keep it by assisting her in halting a war taking place in her sector, the original Lantern for that sector having died during the war. When John is able to help the two sides find a peaceful resolution to their conflict, his new student reflects that, despite John's reputation after destroying two worlds, she now knows that nobody could regret that action more than John himself.
In the New 52, John Stewart joins Guy Gardner, after Hal Jordan's expulsion and Kyle Rayner's departure, as well as others in investigating recent attacks in a distant sector of space, which are revealed to be the result of an old Guardian experiment. At one point, John is forced to kill another Lantern who was about to give in to torture and reveal the access codes to the Oan defense network. John is approached by the Alpha Lantern to arrest him for the murder of Green Lantern member. He is found guilty for this crime and sentenced to death. However Guy Gardner and other fellow lanterns free him before the execution, resulting in the destruction of the Alpha Lanterns when the Green Lanterns refuse to allow John to be executed. During the fights, the Alpha Lanterns realize that all the Alpha Lanterns had become dangerously mentally unstable. Alpha Lantern Varix caused a reaction which killed all the Alpha Lanterns, including himself. During the Rise of the Third Army storyline, John was contacted by the Guardians who state that Mogo's remains appear to be moving and that they have come to the conclusion that Mogo is trying to reform and assign him to track it. While tracking the Mogo fragment's destination, he is discovered by Fatality, who is seeking a sundered love in danger. After they find Mogo's pieces, John had figured out about the Guardians wanting to use Mogo. After the villainous First Lantern is destroyed and the unemotional Guardians are killed off by Sinestro, John has begun a relationship with Fatality in-between on Mogo.