Eclipso is a fictional character, a supervillain in the DC Comics Universe. He is portrayed as having been the incarnation of the Wrath of God, the Angel of Vengeance who turned evil and was replaced by the Spectre. He first appeared in House of Secrets #61 (Aug. 1963), and was created by Bob Haney and Lee Elias.
In the early 1990s, DC revamped Eclipso in a company crossover built around the miniseries Eclipso: The Darkness Within. Here it was retconned that Eclipso was not simply Bruce Gordon's dark half, but a vengeance demon who had possessed Gordon. It also revealed that there was more than one black diamond like the one that allowed Eclipso to take possession of Bruce Gordon. There were in fact one thousand black diamonds that had been passed back and forth among people around the world without even knowing what they were. Originally, Eclipso's soul had been bound inside a giant black gemstone called the 'Heart of Darkness' in deepest Africa, until a treasure-hunter found it in the late nineteenth century. He brought it to London and had it cut into one thousand duplicate diamonds. This weakened the binding spell enough to allow Eclipso to possess anyone who became angry while in contact with one of the diamonds. No longer was he limited to possessing Gordon during an eclipse. This was just a pretense so Gordon would not know the truth about the black diamonds.
Furthermore, Eclipso could also possess multiple people and control them simultaneously. He could possess a person through a diamond and then pass it to someone else and possess him or her too. Eclipso also had the ability to "evoke" shadow-beings rather than possess a person. This happened when the person holding the diamond triggered it with anger, but that person remained passive. A shadow being would leap forth from them, leaving the host in control of themself and Eclipso in control of the shadow being.
When Lar Gand, passing through space, discovered Eclipso's palace on the moon and wandered inside, Eclipso claimed it "gave him a new idea" about possessing all of Earth's heroes and using them towards his ultimate goal, which was ostensibly the takeover of Earth and/or revenge against God for banishing him inside the Heart of Darkness. Why Eclipso hadn't thought of this approach before was not answered; he merely claimed he had spent the last several years "posing as a B-level villain" in order to remain undetected by Earth's heroes and had limited himself to targeting Gordon for the purpose of quashing Gordon's research into solar science. If Gordon had achieved his goal of making solar energy the planet's primary energy source, Eclipso would find it a very inhospitable place to live, as any solar-powered device could be used as a weapon against him.
The climax of the story saw several of Earth's heroes possessed by Eclipso and transported to the moon during an eclipse, another of his new abilities. He then absorbed these heroes into his own body, gaining their mass and also their inherent powers. Gordon led a group of heroes armed with solar weapons to the moon in an attempt to defeat Eclipso once and for all. The absorbed heroes were freed in the end, but only after Starman Will Payton destroyed Eclipso's moon base by detonating his own solar-powered body. Eclipso's diamonds still remained on Earth.
Bruce and Mona are taken on a tour and shown various horrific atrocities, such as dead children in piles. Assisted by the Creeper they manage to escape and form a group of heroes dubbed Shadow Fighters. This group is led by Amanda Waller, formerly of the Suicide Squad. In issue #13 of the series, Eclipso defeats them conclusively, killing Wildcat II (Yolanda Montez), the 2nd Dr. Midnight, the Creeper, Commander Steel, Manhunter IV (a Mark Shaw ringer), and Major Victory. Creeper has returned to action in his own series.
The Peacemaker is also involved in this action. He dies when he crashes the helicopter he was flying, in order to destroy some Eclipso-controlled tanks. These tanks were attacking the sole surviving member of the Shadow Fighter attack force, Nemesis.
It is shown during the series that Eclipso partakes of the occasional chess game with the powerful entity Darkseid.
The survivors of the Shadow Force, those who had not attacked Eclipso directly, reform. Eclipso attacks them with a Parador missile and they barely escape with their lives, using the teleporting power of Nightshade. During the teleportation Mona's father is stolen straight out the window of the vehicle they were in but he later returns alive. The survivors arrive in the United Nations building, just in time to foil another plot of Eclipso, mainly by landing their vehicle on his current victim.
Bruce Gordon and Mona Bennet, would lead the earth's superheros in an attack on Parador, in an attempt to destroy him once and for all. During this attack, it is revealed that the reason Eclipso simply did not kill Bruce and Mona is that they would soon have an important child. The child would grow up, travel back in time and become the one who frees Eclipso from the diamond in the first place. Eclipso dared not kill Gordon or Bennett before they birth this child, lest he create a paradox or at least alter the events, which led to his freedom.
Eclipso's threat was finally removed from the Earth when the Phantom Stranger completes the long task of gathering all one thousand black diamonds from around the Earth and fusing them back together into the Heart of Darkness. This endeavour is occasionally slowed down by the need to combat various Eclipso-caused events, such as the murder of a crew of white slavers. Eclipso is once again trapped. His form, the long-possessed child of Mona and Bruce, evaporates in front of his parents.
The Spectre puts the final nail in Eclipso's coffin by taking the Heart of Darkness from Earth, along with the remains of Eclipso's palace on the moon, burning them to ash with the holy power of God, and casting the ashes into space.
In the Countdown to Mystery series, Eclipso puts a new plan into motion, corupting the heroes Plastic Man, Creeper, and Dove, at the same time tasking a group of homo magi to recover and recombine the pieces of the heart of darkness.
In Countdown to Mystery #3, Crispus Allen, the Spectre's current host, tracks down Bruce Gordon.
In Countdown to Mystery #4, Eclipso once again takes Gordon as a host.
In #5, Bruce is shown to have some control over Eclipso's powers, but can be overwhelmed by his persona if he uses too much at once.
In #7, Bruce manages to free the heroes from their corruption, but is overwhelmed by Eclipso when his ex-wife is threatened. Eclipso then joins with the completed heart of darkness, exponentially increasing his powers, and faces off against the Spectre.
In #8, Bruce, spurred on by Crispus, finally manages to take control of Eclipso, although the two cannot be separated.
Eclipso returned after several years' absence in the "Princes of Darkness" storyline in JSA as an ally of the other shadow-based villains Mordru and Obsidian. Alexander Montez, cousin of Yolanda, vows revenge on Eclipso for Yolanda's death. To this end, he gathers the 1,000 black diamonds, liquifies them, and injects them into himself; all save one, which he keeps to evoke Eclipso. Exactly how Eclipso's diamonds had returned was unknown. Alex covers his body in tribal tattoos he claims he had learned about on Diablo Island. With these tattoos, Montez could summon all the powers of Eclipso by triggering the diamond with his anger, while remaining in control of himself and keeping Eclipso trapped within. As the new Eclipso, he joins the short-lived team of loose-cannon heroes assembled by Black Adam, which was the subject of the subsequent storyline "Black Reign".
During Adam's reign in Kahndaq, Alex becomes romantically involved with his teammate Soseh Mykros, the female Nemesis. However, during a battle, one of Alex's binding glyphs (which keeps Eclipso in control) is broken via a shoulder wound. Eclipso soon kills Nemesis. Alex kills himself in order to prevent Eclipso from controlling him further. This story was significant as it meant that Eclipso no longer had a limitless number of black diamonds waiting out in the world for him to utilize.
Interestingly, this incarnation of Eclipso was never shown using any power but his eye blasts.
In Countdown to Mystery #4, Alex's body is acquired by Eclipso's followers for an as-yet-unknown magic ritual. In #6, all of the black diamond fragments in his body are recombined into their original form.
Eventually, Shazam himself removes Eclipso from Superman by calling upon the hostless Spectre himself to do it. The Spectre forces Eclipso back into a lone black diamond. The Spectre then warns Shazam that he's made an enemy of Eclipso and that the Spectre will no longer defend him. At the end of this series, the black diamond is seen appearing in Jean Loring's cell in Arkham Asylum.
In the Day of Vengeance miniseries, which tied into the Infinite Crisis event, Jean Loring, ex-wife of Atom (Ray Palmer) and murderer of Sue Dibny as seen in the Identity Crisis miniseries, discovered the last black diamond in her prison cell, became the new Eclipso and tricks the Spectre into attacking magic-based heroes as her revenge against Shazam, who was eventually slain while fighting the Spectre. After fending off multiple attacks upon herself, Eclipso-Loring was eventually teleported to a non-decaying orbit around the sun by Nightshade.
In the pages of Infinite Crisis, it was revealed by Alexander Luthor, Jr. that he had sent Superboy-Prime to recover the black diamond, and that the Psycho-Pirate delivered it to Loring on Alex's orders and manipulated Eclipso into manipulating the Spectre. This was all done in the interests of breaking magic down into raw magical energy, which Alexander could use for his own ends. The death of Shazam was particularly useful, as his various champions then became a tether of power; all Alexander had to do was capture one of them, make them say 'Shazam', and they would summon their lightning bolt to power his machine.
In Week Twenty-Seven of 52, Ralph Dibny, on a quest to restore his wife Sue to life and guided by the helmet of Doctor Fate, approaches the Spectre and promises to fulfil any bargain that the Spectre demands in order to restore his wife to life.
The Spectre, desiring revenge on Eclipso for his manipulations of him during the Infinite Crisis but rendered incapable of taking it owing to his present lack of a host, orders Dibny to punish Eclipso in return for his wife's life; Dibny, realizing that this meant punishing Jean Loring, his wife's murderer, and temporarily granted the power of the Spectre, takes Eclipso back to the point at which she (as Jean Loring) murdered his wife and, restoring Jean's sanity, ruthlessly intends to trap her in a permanent time loop and force her to watch herself murder Sue Dibny over and over for all eternity.
Her sanity restored and Eclipso purged out of her, a terrified Loring tearfully begs for forgiveness, screaming that she was crazy when she murdered Sue and that it 'wasn't me!'. Dibny, affected by her pleas, his sense of compassion and his own feelings on watching his wife's death, finds himself incapable of such ruthlessness and refuses to complete his pact with the Spectre, returning Eclipso to her orbit around the sun.
She has most recently been seen in Blue Beetle #16, searching for a new host. Having come to the conclusion that her hosts' corrupted souls are a cause of her failures, she tries to possess a baby with great magical potential and a pure, uncorrupted soul. She is foiled in this attempt by Blue Beetle and Traci Thirteen.
It was revealed in Countdown To Mystery that all of Eclipso's black diamonds were mined on Apokolips millennia ago and that Eclipso was created by Darkseid.
In the recent "The Seduction of the Innocent" ad campaign for DC's Countdown, Eclipso's arm can be clearly seen, with Mary Marvel looking off-page and her face half-shadowed. And indeed, Eclipso is seen in Countdown #38 watching Mary Marvel and plotting to make Mary into her minion. Increasing her anger and suspicions around the other magical being around her, she manages to warp the sunny and cheery disposition of Mary into sheer anger and distrust, and then offer herself as friend and confident. After attempting to make her Darkseid's concubine, however, Mary rebels, and attempts to kill her.
In Countdown To Mystery, Eclipso corrupts more heroes, first Plastic Man and then setting her sights on the Creeper. Mary discovers Eclipso's manipulation of her, and in Countdown #17 she sacrifices her abilities and attacks Eclipso with all her power, leaving Mary and Jean freefalling to the oceans surrounding Themyscira. Loring is last seen sinking into the ocean with a shark approaching, and Eclipso returns to inhabit Bruce Gordon, declaring her lost.