Sentry

The Hoax

Marvel promoted a limited series of The Sentry as an appearance of a forgotten Stan Lee hero of the Marvel Silver Age. This story was, of course, fabricated and further pushed by the comic magazine Wizard: Guide To Comics. The hoax involved a false discovery of lost sketches by artist Artie Rosen of a Stan Lee created superhero predating the Fantastic Four.

Origin

The Power of a Million Exploding Suns

In 2000 a character by the name of Bob Reynolds suddenly recalls that he is the superhero known as the Sentry the man with the power of one million exploding suns. With this recollection he realizes his arch-nemesis the Void is returning to this world and Reynolds immediately begins seeking out Marvel's most prominent heroes to warn them of the coming threat.

Various hero's memories of Sentry were restored as Reynolds talked to them individually. Peter Parker had taken a photo of Sentry that had earned him a Pulitzer prize. Sentry had also flown countless times with Angel to help him overcome his fear of falling. And Hulk had never forgotten Sentry whom he only ever referred to as Golden Man. Sentry had helped Hulk keep control of his rage, later this was to be revealed to be due to a calming aura the Sentry had, and work to be a force for solely good and gaining him public approval. The people eventually remember their own memory about the Sentry, even his former sidekick, Scout.

Most importantly Mr. Fantastic remembers that he and Robert Reynolds had been best friends and that Sentry had often teamed up with the Fantastic Four to fight the world's greatest threats. Over time the general public slowly remember the Sentry and the good he had done for the world.

During the course of an investigation into why the world had forgotten Sentry, Richards and Reynolds make a discovery. That Void and Sentry are two parts of the same torn psyche, and that the reason behind the world forgetting the Sentry had to do with Reynolds using his power to erase the Sentry from the world's memory including his own thus destroying Void once and for all. With the heroes of the world united and waiting for the Void to come, Reynolds comes to the realization that he must make the sacrifice again. With the help of CLOC, Mr. Fantastic, and Doctor Strange he once again erases the memory of Sentry from the world.

The New Avengers

In the first issue of New Avengers it is shown that Robert Reynolds is a prisoner in the Raft, a prison built specifically to house super-villains. He had voluntarily imprisoned himself for the murder of his wife, Lindy Reynolds. During a jailbreak at the Raft, Sentry turns and defends several of the Avengers from Carnage who had beaten several members to a standstill. He easily overpowered Carnage, flew him into the depths of space and tore him in two.

Taking a great interest in the now free Sentry, the Avengers begin investigating his dark persona. They soon realize that the Void is actually the result of a cerebral virus created by Mastermind who was under the direct employment of Crazed General, a villain from the original Sentry story arc. This virus damaged the Sentry's ability to remember any facts of his life, in a cry for help and an amazing show of power, Sentry transferred his memories into comic book writer Paul Jenkins, who transferred those memories into a popular comic book series. Emma Frost released Sentry from the bonds of his virus and he recalls much about his life including that he never actually killed his wife and that his Watchtower stood atop Stark Tower, where he had hidden it from public view subconsciously all along.

With his memory re-instated he joined with the Avengers and began fighting alongside them.

Destruction of The Void

Sentry is introduced as a beloved super hero who has accomplished dozens of heroic acts and saves hundreds of lives on a daily basis. However, his psychological problems have worsened drastically. Unable to deal with the fact that Robert Reynolds, Sentry, and The Void are the same being. Sentry locks the Void in a vault deep with the Watchtower forever. At CLOC's urging, Reynold's psychologist, Dr. Cornelius Worth, enters the vault to find nothing more than a chair and a large mirror. When Reynolds is confronted by Worth about his problems, he flees immediately to the fairground where he first gained his power and often does battle with the Void.

When Worth catches up to Sentry, he instead finds the Void, who claims that he is indeed the true transformation of an ultimately evil Reynolds. Sentry is simply a byproduct of moral guilt for all the lives that Void has claimed. The Sentry emerges as the prominent persona and with only half of Reynolds' memories (Void has the other half) he isn't truly sure that the Void is incorrect in his statement. He reveals to Cornelius that he actually hired him to reveal the Void's existence to the world so he would no longer be forced to deal with the struggle of hiding him. The Sentry then reveals the true way he gained his powers. He ingested a super soldier serum developed in order to get high as a teenager. He finally reveals that he knew all along that the Void has not in the vault, but that as long as Reynolds believed so, that the Void would remain dormant.

In a battle in the antarctic the Void reveals that the serum Sentry ingested was actually super-saturated, exponentially more potent super soldier serum than what created Captain America. This was considered dangerous by SHIELD because Sentry's blood could be used to create enough serum to power the entire world population and that several attempts had been made on both the Void and Sentry to kill him. Enraged by this news the Sentry flies into space and hurls the Void into the sun, claiming that he was no longer needed to balance out his acts of good. The Void swore to return.

Reynolds and the Civil War

Sentry allied himself with Tony Stark and the Pro-Registration Mighty Avengers. He fought alongside Iron Man on many occasions, often being considered the most powerful member, but untrained in the use of his powers. When confronted by Wolverine regarding his choice of alliance Sentry claims that he must stop this messy business even if it means becoming part of it for a while. He knocks him out and leaves him for SHIELD agents to bring into custody. Believing that for every action he make cost the lives of everyone he knows, Sentry then left earth and confronted the Inhumans. He was ordered to be in Black Bolt's presence and Sentry told them about the events of the Civil War dividing the superhero community and also tried to continue his romance with Crystal. Iron Man came to him and agreed to sign up for registration. He appeared in a press conference supporting the Super-Human Registration Act just before the final battle.

World War Hulk

Sentry's watchtower, on top of Stark Tower, was destroyed when Hulk and Iron Man first fought in New York. Mister Fantastic make a machine that will duplicate the soothing aura Sentry use to calm down Hulk but he wasn't fooled by it. All the while, Invisible Woman and the President tried to call the real Sentry but ignores their plea. After seeing Hulk in the TV deciding judgment to force Mister Fantastic to kill Iron Man, in roman-style of gladiator battle, Sentry finally decided to fly to New York to stop Hulk remarking, "It's time to play God." When Sentry arrived, he engaged the Hulk and so much energy was being released that they both reverted back to their normal human state and Bruce was able to knocked out Robert with a weak punch.

Post-Civil War

After the Civil War, Tony recruited Robert to the Mighty Avengers, the new incarnation of the Avengers. He was described as the most powerful member but is inexperienced in using his powers. In a battle against Ultron, the proves to be a draw until Ultron sends a virus to take down the Helicarrier. After which she initiated an assassination of Sentry's wife.

Enraged and looking like the Void persona, Robert attack Ultron mercilessly until Ares had to knock him out and let Ant-Man introduce a virus in Ultron programming to shut her down. But Sentry would not relent on attacking Ultron, so much so that he almost decapitate her head while the virus has not yet been completely uploaded. It wasn't until Ms. Marvel knocked him out. After Ultron's defeat, Sentry rushed to his watchtower to see his wife alive and well. Later, Tony was shocked and terrified on Lindy's request to either de-power or kill her husband.

When the Mighty Avengers confronted Doctor Doom for the Symbiote attack in New York, a time machine took Iron Man, Doom and Sentry back to the "Silver Age". Sentry goes to the Baxter Building to retrieve Mr. Fantastic's time machine in order to return to the present time line. After knocking out the Thing, the trio returned to the present and resumed their fight. Sentry then subdued Doom and took him in SHIELD custody.

Secret Invasion

When the Mighty Avengers investigated a Skrull spaceship that crashed in the Savage Land, They discovered whats inside the ship are some of the superheroes that could have been possibly replaced by Skrulls. When Sentry battled the Vision, he transformed into the Void. the Void told him that the invasion was his punishment for wiping out everyone's memory. Sentry panicked on his what he saw and fled in the middle of the battle to Saturn where he dealt with his fragile mind. The Skrull thought that the Sentry is the most powerful and that the only way to deal with him is to induce a mental breakdown. When the Skrulls invaded New York, they attacked the watchtower where Sentry's wife is in. When the Skrull was about to attack, Lindy was defended by Sentry in the form of the Void. He boasted to her that whatever he cannot do, he could as the Void. After the Invasion, Sentry was approach by Norman Osborn and they talked about Reynold's mental issues. Norman tells the Sentry that the Void is just his imagination and that he will help deal with these issues on the condition that he join in the newest incarnation of the Norman's Avengers, the Dark Avengers. Robert agrees.

Dark Reign

Powers

The Sentry is one of the most powerful superheroes in the Marvel Universe. His own personal statements of his power often have him stating that he has the power equal to one thousand or one million exploding suns. Spider-Man stated that Sentry fought Galactus to a standstill (very debated subject due to Spider-Man's penchant for satire and hyperbole). Sentry's superhuman strength has enabled him to engage beings such as a fully enraged Hulk. However, that fight resulted in both individuals reverting back to human form.

Sentry also possesses super speed. This allows him to perform such feats as catching a bullet and flying from the Earth to the Sun and back in a matter of minutes

It has also been observed that Sentry has extremely heightened senses. This is evidenced by Sentry's statement that he could literally hear the heartbeat of a butterfly in Africa while he himself was still in New York.

Sentry is also one of the few superhumans to be considered invincible. Other than his fragile mind, SHIELD and even Iron Man have not been able to find any other areas of physical vulnerability. 

According to Emma Frost, Sentry is one of the most powerful telepaths on earth. Once, he wiped the memory of every person on the planet of knowledge regarding his existence. Most of Sentry's mental abilities are used to maintain his physical form.

Under extreme emotional distress, Sentry can resurrect another being. This was first manifested when Sentry brought his wife back to life by just his touch. Originally, he was not even aware that he had this ability. He was shocked that he even had it. Even now, Sentry does not have full control over this power just yet. He could also emit a wave of radiation that can calm the Hulk down.

During the Civil War, Spider-Man and a group of SHIELD agents ranked Sentry as the most powerful of all Earth's heroes, with the Hulk ranked as second and Black Bolt ranked as third. While this arbitrary ranking is at best debatable (particularly given the events of World War Hulk), the Sentry is nevertheless one of the most powerful metahumans on the planet, and has even been called by Norman Osborn as a "living H-Bomb."

As the Void, Robert has completely different powers. They can be seen on the Void's page. It is thought by many that Robert is even more powerful as the Void than he is in his Sentry incarnation.

Alternate Realities

Marvel Zombies (Earth-2149)

The infection started when a version of Sentry from an alternate universe who was already a zombie. He first ate those who were ascending in heaven, until Ash confronted him and shot him in the face using his shotgun. Unfazed, Sentry punched Ash strong enough, that he he reaped through the fabric of reality, thus sucking both Ash and Sentry in Earth-2149. Warped into New York City by tearing an hole in reality itself and started looking for food. His first victims were the Avengers consisting of Colonel America, Luke Cage, Hawkeye, Black Widow and Ms. Marvel, for they were the first at the scene of the crash site. Shortly after, the virus that he spread had reached to every superhuman in the world,what happens to him after the world is consumed is unknown, but probably opened another hole on the fabric of reality and escaped. 

Later another man called Robert Reynolds (THIS dimension Bob, who seems to have no powers) appears as one of the fell survives with the acolytes, Black Panther (another uninfected hero) gives him the Wasp head and alerted him to be cautious or he could be bitten. Years later an older version of him returns to earth in Marvel Zombies 2 (Wasp appears among then on a suit designed by Bob which would be later used by Hawkeye too).

When the Marvel Zombies attacked the Hulk reverted to Bruce Banner and is put on analysis by Bob. Later it is revealed Robert and Forge used T'Challa's son's body to host Colonel America's brain (but still he had problems to act as the original, but remained the fighting skills) this makes Black Panther attacks both, but he is stopped by Colonel (who almost killed him, but was stopped by Bob). Eventually when the zombies returns the heroes (now with Spider-Man and Luke Cage on their side) fight the zombies to prevent then from entering the space ship where the last humans were.
While repairing Luke and Spidey's damages (Spidey was ripped in two by Gladiator) he kisses Wasp and says what he felt Wasp then grabs him and kisses his mouth (making the others surprised, but she just said "what?")

While watching everything Bob is attacked by the zombie Bruce Banner who somehow managed to escape his prison the attack made Bob accidentally open the force field, but somehow manages to escape the zombie. Later when the zombies realizes their hunger has gone it all looked like the saga arrived an end... But then the zombie Hulk attacks then and tries to feed on the humans. Thought the fellow zombies said he should stop Hulk did not listen then and a fight start. Thought the zombies efforts Hulk was starting to get the upper hand and kills Firelord, Iron Man, Phoenix and Hawkeye but Bob arrives and sacrifices himself to Hulk. Black Panther tried to stop him, but Bob said he didn't had reason to live anymore (he believed Wasp was killed by Goliath, but she later reappears as a head) and it was the only way.after getting eaten, the zombie reverts to Bruce Banner who asks for the others kill him, what the zombies do knowing it was the only way to stop this. Later Goliath (Henry Pym) asked Wasp's forgiveness and said he felt sorry for Wasp and she answers by saying he was the greatest man she ever knew and cared for everyone else not just her, Goliath just answers "You always knew how to make me feel small".

note: the zombie that infected the world don't have any relation with the one that sacrificed to Hulk, despite the name

House of M (Earth-58163)

Ultimate Universe (Earth-1610)