The idea of the Ultimate Lifeform or Perfect Being is a common one in anime, espoused by many villains who claim they've reached the absolute pinnacle of power in their respective universes. Being an ultimate lifeform can mean a lot of things, from bioengineered creatures to near-godly beings, but the main point is that they're so absurdly powerful that the heroes don't stand a chance--or at least, that's what they'd like the heroes to believe.

An Ultimate Lifeform is often the final enemy in a story, but it doesn't have to be. Ultimate Lifeforms often have grandiose plans for reshaping the world in their own image, which is generally bad for anyone who doesn't fit into their vision for utopia. For some, that means scrubbing the Earth of all those it deems inferior, while for others it may mean creating a new race of superbeings to supplant the existing society. They're often extraordinarily difficult to defeat, and may require particularly desperate measures to deal with. Here are 10 of the greatest Ultimate Lifeforms to ever appear in anime.

10 Tomura Shigaraki Became the Ultimate Quirk Vessel

Series: My Hero Academia

Tomura Shigaraki was once a fairly normal human with an exceptionally powerful Quirk, but during season 6 of My Hero Academia, he underwent biological augmentation at the hands of Dr. Garaki in order to become the ultimate vessel for All for One's Quirk. His body is exceptionally resilient, and he's able to wield literally hundreds of Quirks, whereas most people will begin to lose their minds after just three. During the final battle, Shigaraki's body began to mutate, searching for a new form more suited to wielding the colossal power that rests inside of him.

Shigaraki is said by Dr. Garaki to be the epitome of the Quirk Singularity theory, an ultimate being whose power is absolutely unrivaled by any that came before. All for One intended for Shigaraki to become his new body, one befitting a demon lord who rules over humankind with an iron fist.

9 Muzan Kibutsuji Believes Permanence is Perfection

Series: Demon Slayer

Muzan Kibutsuji is the original Demon who has lived for over 1,000 years. He's extraordinarily powerful and possesses regenerative abilities that are completely unmatched. He has the power to convert other people into demons with his blood, and can do just about anything--except set foot into the sunlight. Muzan detests change, seeing all change as decay, and views permanence as perfection. And, since he's been around for so long, that makes him the most perfect being on the planet.

Muzan detests change, seeing all change as decay, and views permanence as perfection.

Even among the other demons he has created, no one comes close to the level of power which Muzan possesses. His only goal is to conquer his one remaining weakness, therefore making him truly eternal, and thus perfect in every way. Muzan will do anything and everything in his power to accomplish this goal, with morality and human life no obstacle.

8 Sosuke Aizen Wielded Unlimited Power

Series: Bleach

Sosuke Aizen is arguably the greatest villain Bleach has ever seen. Even as a Soul Reaper, he had tremendous power, but upon fusing with a mystical object known as the Hogyoku, Aizen gained dominion over souls, able to create the beings known as Arrancar. The Hogyoku granted Aizen seemingly limitless power and regenerative ability, and as he harnessed that power during the Fake Karakura Town arc, Aizen began to mutate and take on new forms, which only assured him of his superiority over both Soul Reapers and Hollows. Aizen's spiritual pressure becomes so great that substantially weaker beings are instantly turned to dust in his presence.

Aizen is eventually defeated by Ichigo's own incredible growth, although his defeat comes at a high price, as Ichigo loses all his Soul Reaper powers and abilities in order to do so. Even then, Aizen can't be killed; only imprisoned eternally.

7 Father Harnessed the Power of the Gate of Truth

Series: Fullmetal Alchemist

Father is a homunculus who is thousands of years old, and who aspires to become a god in his own right. He sacrifices nearly the entire nation of Amestris to gain the power to conquer the Gate of Truth, the source of all Alchemy in the world. In this form, almost nothing is beyond his reach, and if it hadn't been for the incredible foresight of Hohenheim, he would've succeeded in his goal. However, thanks to Hohenheim, his sacrifice is reversed, leaving him with only the power of a single Philosopher's Stone, which simply can't control the boundless power of the Gate.

As Father's power is rapidly consumed, he is eventually left at the mercy of Truth, a being with very little mercy at all, and he is absorbed into the Gate, disappearing for good.

6 Tetsuo Achieves the Pinnacle of Human Ability

Film: Akira

Tetsuo starts out the movie as an ordinary boy who is experimented upon against his will, and after escaping begins to develop extraordinary psychic powers. He's seen as such a threat that the military is after him, as well as his former friends who are at least initially still hoping to help him. Tetsuo's power absolutely overflows, granting him dominion over essentially the very fabric of reality. However, Tetsuo is consumed by his own power and mutates into an abomination, necessitating the interference of Akira, another psychic who had ascended beyond mortal form.

Tetsuo ends up ascending beyond the mortal form due to Akira as well, and is implied to literally become a god, perhaps making him a rare example of an Ultimate Lifeform who actually transcends.

Akira won the Silver Scream Award at the Amsterdam Fantastic Film Festival in 1992.

5 Mewtwo Was Created to Be the Ultimate Pokémon

Film: Pokémon the Movie: Mewtwo Strikes Back

Mewtwo is stated in the film to have been created to be "the world's most powerful Pokémon," and he certainly showcases that power in the film. Mewtwo creates a massive hurricane centered on his island, which is threatening to destroy the entire world so that Mewtwo can repopulate it with cloned Pokémon like himself. Mewtwo has incredible psychic powers, is absurdly fast and intelligent, and has a drive that few other Pokémon are known to possess, even today. He's also one of the few Pokémon ever shown to command other Pokémon in battle.

Mewtwo, unlike many on this list, managed to realize the error of his ways before it was too late, and opted for a life of peace and isolation alongside his clones. Mewtwo's abilities still draw those seeking power to hunt for it, but Mewtwo is more than capable of dealing with them.

4 Ragyo Kiryuin Abandoned Her Humanity for Alien Power

Series: Kill la Kill

Ragyo Kiryuin is the evil mastermind of Kill la Kill, a being who was experimented upon using the alien Life Fibers, which ultimately took over nearly her entire body. Ragyo is functionally immortal, only able to be killed if every Life Fiber in her body is severed, something that only the scissor blade is even capable of. Anything less than a fatal blow is useless. She wields tremendous power to boot, able to easily defeat her daughter Satsuki even while wearing a Kamui (Life Fiber-empowered clothing). Ragyo even calls herself the Ultimate Lifeform within the series, taunting the heroes.

Ragyo's power was only able to be countered thanks to Ryuko wielding similar power, and even then it was an uphill battle, as Ragyo had far more experience.

3 Meruem Evolved into The Ultimate Nen

Series: Hunter X Hunter

Meruem is the King of the Chimera Ants, a species which is capable of absorbing traits from the beings that they eat, mutating them in unpredictable ways. Meruem was considered almost from his birth to be the strongest Chimera Ant to ever exist, and he proved that repeatedly in battle by defeating nearly every Hunter sent after him. Meruem could steal the Nen abilities of those he devoured, giving him such a wide range of abilities that fighting him one on one was hopeless even for Netero, the most powerful Hunter there is.

Meruem even withstood a nuclear explosion at point-blank range, although he was ultimately killed by the ensuing radiation poisoning, one of the few things he had no resistance to.

2 Perfect Cell is Called Perfect for a Reason

Series: Dragon Ball Z

Cell was created to be an Ultimate Lifeform by Dr. Gero, using the DNA of a wide range of species, including Saiyans, Namekians, Frieza, and more. This gave him abilities like incredible regeneration (coming back from even a single surviving cell) and the capacity to grow stronger when nearing defeat. When Cell absorbs Androids 17 and 18, he achieves his "Perfect" form, wielding such overwhelming power that he set aside his plans for destruction and domination for the Cell Games out of sheer boredom. Cell is also exceptionally intelligent in his Perfect form, meaning cheap tricks are unlikely to work.

Cell was ultimately defeated after coming back numerous times by Gohan's Father-Son Kamehameha attack, which managed to incinerate every single cell in his body, thus preventing his regeneration for good.

1 Kars is the True Ultimate Lifeform

Series: Jojo's Bizarre Adventure: Battle Tendency

Kars is a Pillar Man, a type of being that was already leagues stronger than any human, but he ascended to the status of Ultimate Lifeform after donning a Stone Mask equipped with the Red Stone of Aja. Kars' abilities became hundreds of times better than they already were, allowing him to rapidly outmaneuver Joseph, and his previous weakness to sunlight was gone, rendering Joseph's Hamon useless. He could mutate his body on a whim, and regenerate from any injury, no matter how severe. Joseph's defeat of Kars came down to sheer luck, managing to eject him outside the atmosphere through a volcanic eruption.

Kars' perfect survivability ultimately backfires on him, as he is stranded in deep space, unable to move or escape for eternity. It's said his mind eventually shut down out of boredom, yet he still floats along in orbit, technically alive. This makes Kars without a doubt the best Ultimate Lifeform to ever appear in anime.