He revealed himself to the Fantastic Four when they discovered his home, telling them he would leave the Moon to observe humanity from a more distant area.

[10][11][12] His most notable transgression was in Fantastic Four #48, in which he tried, and failed, to prevent the Silver Surfer from bringing the planet-devourer Galactus to the Earth.

[16] During the GLX-Mas Special, Uatu appears in Wisconsin, after Squirrel Girl and her sidekick Monkey Joe defeat Thanos.

[21] Since these events, Uatu has restricted himself to appearing to observe particularly cosmic events in the Marvel Universe, such as visiting the heroes prior to the vote on the Superhuman Registration Act,[volume & issue needed][22] the final battle of the "Secret Invasion" storyline,[volume & issue needed] and the Hood's acquisition of the Infinity Gems,[volume & issue needed] reflecting during these appearances that he cannot do any more or he may be taken from Earth altogether.

[volume & issue needed] Uatu later visited Red Hulk at the time when he was on an asteroid helping Thor to close a black hole.

After being unable to find him, Uravo informed Yruku and the other Watchers that he thinks Uatu has become unhinged ever since Red Hulk attacked and absorbed some of his powers.

[30] The 2014 "Original Sin" storyline reveals that Uatu's father was the Watcher who originally gave nuclear technology to the Prosilicans, and that Uatu's observation of parallel universes is motivated by a desire to find the one world where his father's act of charity was proved to be the right thing to do.

[31] In the beginning of the story, Uatu is murdered, and his eyes are gouged out, setting off a search by the Avengers and their allies for his killer.

[33] Nick Fury eventually reveals that he has spent decades in a secret one-man mission to single-handedly confront and kill alien, subterranean, and extradimensional beings that threaten the Earth, and that, with the Infinity Formula having been depleted from his body, he has experienced rapid aging and wishes one of the superhuman investigators who have confronted him to take his place before his imminent death.

Once he began analyzing them, the Unseen realizes the weapons were created by the First Race and is overcome with energy as the one-eyed Uatu is brought back to life.

Uatu is horrified at this apparent proof that he broke his vow for nothing, and his father then leaves him to watch this alternate universe for the rest of his existence as punishment for his interference, while the rest of the Watchers remain resolved not to get involved in the coming war (unaware that Nick Fury is watching them and plans to take action himself).

[41] Revealing that the Prosilicans' weapons were based on Watcher technology and they were responsible for the devastation of the Great Barrens, Uatu absorbs the power of the Apex- the centre of all power and knowledge of the Watchers- becoming the personification of his race's power, allowing him to restore the Barrens to lively space after Reed Richards uses the Ultimate Nullifier to stop Wrath, the leader of the Reckoning, with the remaining leaders (as well as the one Watcher who knew the full truth and kept it from the rest) trapped in the M'Krann crystal as punishment.

These abilities include flight, telepathy, energy-manipulation powers, power-negating force-field projection, illusion casting, the ability to psionically alter his appearance at will, and highly advanced cosmic senses allowing him to be aware of countless events of Earth.

Bolstered by treatment with "delta-rays", Uatu possesses virtual immortality, although he can die by losing the will to live.

[44] Watchers can augment their strength with cosmic psionic energy if they choose to; however, they tend to minimize their physical activities.

The 1985 edition of the Official Handbook of the Marvel Universe compared Uatu's scale of power to that of Galactus, the Stranger, Odin, and Zeus.

[volume & issue needed] Uatu received a highly extensive education in his youth on his home world.

His home on the Blue Area of the Moon contains an enormous array of weaponry, artifacts, and technology created by various alien races from throughout the universe.

[volume & issue needed] The 2003 miniseries Marvel 1602 reveals that, although The Fantastic Four #13 was the first time he broke his oath, the anomalous appearance of Marvel's superheroes more than 300 years early — speculated by Uatu to be the result of the universe trying to create the means to save itself from a temporal anomaly — forced him to severely bend his oath by communicating with the 1602 version of Doctor Strange prior to the latter's death.

Though Uatu wanted to have them destroyed, he was talked out of it by the 2099 version of Moon Knight and the clones established themselves as this time period's Fantastic Four.

[47] On the unified Marvel 2099 reality of Earth-2099, Doom made everyone forget about the Heroic Age and imprisoned Uatu so that he can inform him about possible threats to him.

He eventually congratulated the Sandman for his help; Flint Marko had destroyed all the other mobile zombies by dispersing a nanite cure devised by Spider-Man.

Watts encounters non-powered versions of Spider-Man, Wolverine, and Daredevil, who face problems similar to their super-powered counterparts from Earth-616.

Just as in Earth-616, Uatu finds that he cannot remain detached and watch as his patients' lives are ruined, and tries to come to their aid,[52] but, like his original incarnation, he never acts directly, instead inspiring and guiding the heroes.

[volume & issue needed] The Ultimate Marvel version of Uatu is not a person, but a highly advanced alien computer that observes everything.