Alan Moore's Watchmen was a touching love letter to congestion and genre within the comic industry and the overzealous nature of Cold War America. Within it, he crafted all manner of superheroes that would model the hyper-idealized selves that superheroes had been made to be at the time.
This has come to mean the unbending Rorschach, the overly-commercialized Ozymandias, and, as this list will examine, the scientific god that was Dr. Manhattan. He can see the future, reconstruct matter, and teleport to far expanses of the world at will. Within even the outrageous standards of the anime world, Dr. Manhattan is a beast. However, there are a golden few among the anime ranks that can take on the personified Armageddon. This list will be running down 5 anime characters that Dr. Manhattan can surprisingly beat but also 5 that he definitely can't.
10 Can't Defeat: Madoka Kaname
The godly personification of nuclear fallout and an idol of American military strength is no match for the awesome might of...a magical girl. Dr. Manhattan is an all-powerful being, but his only domain is that of this reality. Having made a wish to change the desires and needs of an entire, higher being, Madoka Kaname had to be gifted the powers of an all-powerful god, overseeing the realities and causalities of multiple worlds to ensure the fate of her world's magical girls aren't spread anywhere else.
Puella Magi Madoka Magica was a pivotal installment within a long line of magical girl anime, not only allowing the genre to enter grittier writing but also reach existential, destructive feats to outclass even Alan Moore's imagination.
9 Can Defeat: Naruto Uzumaki
Naruto Uzumaki is one of the leading figures among Shounen anime. Beyond just exemplifying themes of friendship and an incredibly positive attitude, Naruto is a premiere Shounen protagonist for all of his incredible feats of strength. He's mastered ninja cloning and the complex, destructive Rasengan.
He's even honed and tamed the demonic power of the Nine Tailed Fox. However, for all his advanced martial arts skill and magical power, Naruto is still limited to the fragile and limited body of a human being and the intelligence and imagination of, well, Naruto Uzumaki. Beating him in both brain and brawn, Dr. Manhattan can beat the Hidden's Leaf's infamous knucklehead.
8 Can't Defeat: Saitama
It's kind of hard to give Saitama any specific gauge to position him next to Dr. Manhattan given the fact that his entire gimmick centers around just taking out his opponents with one punch. If anything, rather than describe the limits of what he has done, Saitama has proved his worth against Jon Osterman in what he has outlived. He's faced the likes of giants, catastrophic mosquitos, and, possibly his best feat known in the anime today, a malevolent alien being with a regenerative ability and power to surpass the human imagination.
All of the above have had a hard time just giving Saitama a scratch; and as the series has suggested time and again, Saitama was able to beat all of them with a few punches. With abilities and feats that seem extended beyond rational reality, Dr. Manhattan doesn't seem to have anything ludicrous enough to circumvent the living gag.
7 Can Defeat: Gilgamesh
In the Fate series, Gilgamesh is well-known as history's first and greatest hero. Having conquered all manner of foes during his heyday and having amassed a vast armory of legendary weapons, Gilgamesh is a near insurmountable warrior. That legend was only extended with his incredible magical power seen in the Holy Grail Wars.
However, as overpowered as he is in Fate, he almost certainly doesn't have a sword or spear that could do any damage to living nuclear fallout. Capable of turning any and all of Gilgamesh's weapons to mush and able to predict all of Gilgamesh's moves, Dr. Manhattan would more than prove why Gilgamesh's methods have gone extinct.
6 Can't Defeat: Haruhi Suzumiya
If being weak to magical girl wasn't enough, Dr. Manhattan doesn't even stand a chance to the spoiled whimsy of a bored, high school girl. Haruhi Suzumiya is a godly anomaly dictating and overriding the worlds of the future, espers, and aliens.
If she wants something, it will happen, and it's just unfortunate that she kind of just wants intergalactic chaos, a never-ending summer, or, for some reason, a murder mystery. Haruhi seems to exist only in the realm of her own rationality, something that seems to circumvent the physics and causality and Dr. Manhattan's powers. As powerful as the doc is, he has no rational means of combating Haruhi's melancholy.
5 Can Defeat: Undead Ban
When The Seven Deadly Sins entered the stage of Shounen anime, it delighted fans with a clinic of exaggerated, hyped power moves. Several of the series' magical beings and super strong knights could land on this list for being overpowered but perhaps the greatest challenge for Dr. Manhattan would be the thief and vanguard of the Sins himself, Undead Ban.
Beyond his incredible fighting talent and superhuman strength, Ban has also drunken from the Fountain of Youth, not just granting him incredible regenerative abilities but eternal youth. Despite his seemingly immortal blessing, Dr. Manhattan would still likely be able to tear Ban apart, atom by atom. To be fair, Ban may live through this process, but he won't live well.
4 Can't Defeat: Ryuk
While Dr. Manhattan may be able to bypass the limitations of an immortal human, the same can't be said for an immortal, death god. Death Note's Ryuk is a godly being who oversees the fates of humanity.
Seeming functioning outside the bounds of humanity and perhaps even reality, Dr. Manhattan doesn't really have anything in his arsenal that could disintegrate the apple-loving guy. Dr. Manhattan, however, does exist within the earthly realm of life and consciousness that Ryuk so happens to look over. Having just to write Osterman's name, Ryuk has this guy beat.
3 Can Defeat: Light Yagami
While being able to kill anyone and everyone on a whim may make someone overpowered, it doesn't necessarily mean that they're also invulnerable. Kira was a seeming godly figure among the citizens of Death Note's world, but he was essentially just a slightly smarter high school kid who god a hold of a very strong gun.
In the battle between Light Yagami and Dr. Manhattan, the outcome is very dependent on whether or not Light could write down Jon Osterman's name before the boy in glowing blue would figure out his intent. However, in all likeliness, Dr. Manhattan could probably use his omnipotence to circumvent the Death Note, especially if Kira had already been on his infamous killing spree, signaling to Jon that there is danger afoot.
2 Can't Defeat: Zeno
Dragon Ball is host to a variety of overpowered characters and near omnipotent gods. However, if there was one to stand above all the rest as the ultimate and last being, it would the Omni-King Zeno.
Though his entire look screams Dragon Ball's next line of plushies, that adorable face hides a bored god who really likes hosting fighting tournaments between the dimensions he oversees. He is the ruler and manipulator of the differing realms that the seemingly all powerful Saiyans, Androids, and Majin Buu could only reside in. Facing perhaps the actual god pulling all the strings, Dr. Manhattan may truly feel like a puppet in this one.
1 Can Defeat: Son Goku
However, as omnipotent as Zeno may be, he isn't exactly granting special, godly favors to the actual main character of Dragon Ball. Son Goku, by all means, is a mortal character whose defining quality is apparently being able to surpass his previous, cosmic level limits.
However, as insanely destructive and strong as he might get, it's a superficial strength that still requires incredible effort and time on his part. As a being of matter, reality, and nature, Goku and his molecules are very susceptible to Dr. Manhattan's reality bending manipulations. A Saiyan, in this instance, is nothing more than just a flying ant to Watchmen's god.