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I will kill the gods.

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You may have defeated Zero, who I sent ahead of me, but he succeeded in killing the gods. Why do you think that is? It was so I could give everyone the power of magic equally. And why did I kill your empress? It was to destroy the current world order. Now, do you wish to serve someone? Or do you wish to live for yourself? The time has come to choose where this world is headed. This is the final war and I am this world’s last demon king.

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I don’t just want to save the beings inside me. I want to save all the beings inside the Law of Identity’s universe. I want to free them from the stories. That is my wish.


Akuto Sai is the primary protagonist of Ichiban Ushiro no Daimaou. He is an orphan who transfers into Constant Magic Academy, hoping to someday become a High Priest for the benefit of society; however, upon arriving, the school's oracular spirit predicts that he will become a Demon King in the future. Eventually, Akuto decided to start his crusade against the gods, taking onto the mantle of the Demon King.

Powers and Stats

Tier: 9-A | 8-C | At least 8-C, Low 2-C without limiters | Low 2-C | At least 9-A, likely 8-C when sealed, Low 2-C when unsealed | High 1-B | 1-A | High 1-A

Name: Akuto Sai, A-chan, Demon King, Evil Itself, Last Demon King, Cursed One, Ruler of Ghosts, God Universes, Master

Origin: Ichiban Ushiro no Daimaou

Gender: Male

Age: 15 | Unknown within the Afterlife, but it's stated he spent several decades within it | At least 10 thousand years old, though technically the concept of time is meaningless to him

Classification: Constant Magic Academy student, Public Morals Officer, Demon King, Artificial Human, Priest of the Church of Purity, Storyteller

Powers and Abilities:

Superhuman Physical Characteristics, Magic, Explosion Manipulation, Absorption (Can absorb magical energy from other beings), Forcefield Creation (Can cover his body with a mana barrier), Aura (Can twist limbs to break them with the pressure of his mana), Paralysis Inducement (Can control the mana surrounding other people's bodies to paralyze them), Telekinesis (Can levitate his opponents' bodies into the air), Immortality (Types 4 and 8; The Law of Identity doesn't allow his complete death)

All previous, Energy Projection (Can create mana balls), Light Manipulation, Air Manipulation (Can create small tornados, whirlwinds and typhoons), Homing Attack, Statistics Amplification (Can pump mana into his muscles to increase his physical prowess), Extrasensory Perception (Can detect the mana patterns of individuals, allowing him to sense them without seeing them), Martial Arts, Gun Mastery, Heat Manipulation (Boils down the mana inside his body to emit heat), Power Mimicry (Copied Yuzou's illusions by seeing them), Illusion Creation (Can show people illusions of their death, and some have died from the shock left by the illusion), Precognition (His illusions allow him to predict his opponent's next move), Corruption (His ominous mana can corrupt living beings, turning them into Demonic Beasts, as well as inorganic matter, such as turning a school into the Demon King's castle), Rage Power (His anger causes his mana to explosively increase), Teleportation, Regeneration (Low-Mid, Regrow his left arm after it had been severed), Limited Spatial Manipulation (Held together the space cut by Bouichirou)

All previous, Regeneration (Mid, He regenerated half of his body after it was blown away by a plasma explosion), Animal Manipulation (His ominous aura allows him to control Demonic Beasts), Kakei (A fighting style based on minutely controlling the mana and turning aside his enemy's power), Can create a mana projection of himself to avoid damage, Healing, Electricity Manipulation (Can strike his foes with lightning)

All previous to a vastly higher degree, Flight, Telepathy, Can cause his opponents to explode with a glare, Longevity (Stated to be able to fight Zero on the moon for centuries if it came down to it, and is said to have transcended the concept of aging), Self-Sustenance (Types 1, 2 and 3), Power Nullification (Can nullify mana attacks)

All previous, Enhanced Senses (He can grasp the location of every single mana particle in the air and has x-ray vision), Size Manipulation (He can shrink his opponent to microscopic sizes), BFR (Can seal his opponents in a virtual alternate dimension)

All previous abilities to an infinitely higher degree, Analytical Prediction (Can predict his opponent's next moves based on their body expression), Pressure Points (He's able to hit his opponent on a special part of their forehead that causes their brain to stop functioning), Subjective Reality (Can project his desires into the reality of the Afterlife), Time-Space Manipulation (Can bend the entire Afterlife around himself to reduce it into nothing), Acausality (Type 4; The Law of Identity stated Akuto can choose what is real and what is fictitious to the point of contradicting causality),

All previous abilities to an higher degree, Conceptual Manipulation (Type 1; Created the concepts of comunication, the second and third person), Acausality (Type 5; Exists outside of the causlity system of the stories of the Extra-universal Gods), Creation (Can create stories), Probability Manipulation (His stories are based on the infinite possibilities), Plot Manipulation (Has full control over every story, editing their plot to his will), Reality Warping, Higher-Dimensional Manipulation (Has full control over stories, which are structures that contain an infinite retreat of dreams within dreams within dreams), Soul Manipulation (Controls the souls of every being within his stories), Information Manipulation, (Is able to turn souls into mere concepts/data fitting the stories given by him), Perception Manipulation (His creations can only be truly perceived by reaching them), Large Size (Type 11; Perceived his creation as only a piece of paper on an infinitely vast room), Beyond-Dimensional Existence (Type 2), Physics Manipulation (Created all the fundations for the laws of the stories he created), Causality Manipulation

All previous, Void Manipulation, Nonexistent Physiology (Cast aside his earthly form, leaving a void where only emptiness resides)

Attack Potency: Small Building level (Caused a magical explosion that destroyed Class A's classroom and a magical barrier while holding back, and later on, he created an even bigger explosion which was able to create a crater 5 meters across) | Building level (Can fight robots who can destroy building, Exchanged blows with Peterhausen) | At least Building level (Upon deciding to kill the gods, Akuto became the Demon King, unlocking his true power and becoming much stronger than before), Universe level+ without limiters (Killed Suhara, one of The Computer Gods) | Universe level+ (As an Awakened Demon King, he should be able to kill the Computer Gods, in addition to having fought Zero) | At least Small Building level, likely Building level when sealed (Scaling from his durability), Universe level+ when unsealed (Stated to be equal to The Formless Power, which is more powerful than the magic system of the Computer Gods and black magic combined) | High Hyperverse level (Comparable to The Extra-universal Gods) | Outerverse level (Has full control over the Aftelife, a realm that exists in a system above an infinite retreat of dreams within dreams within dreams, and was able to completely destroy it) | High Outerverse level (Casted aside his earthly form, leaving a void body that was take into Keena by the Contract of the One, which allowed him to be freed from his story role as the Demon King and become part of the Anti-Universe, the place where all stories end, which would put it above the totatility of fiction)

Speed: Peak Human (Can cross 10 meters in an instant) | Subsonic (Blocked Lily Shiraishi's punch) | Supersonic (Can keep up with Bouichirou Yamato), higher without limiters | At least Supersonic (Much faster than before) | Subsonic when sealed (Can keep up with Lily), At least Supersonic when unsealed | Immeasurable | Omnipresent in the afterlife. Irrelevant otherwise | Irrelevant

Lifting Strength: Unknown | Class 50 (Threw a 30 meters tall robot to the ground, and shouldn't be much weaker than his sealed Act 10 self) | Class M (Lifted Genkaku) | At least Class M | Class 50 when sealed (Lifted an excavator on one hand), At least Class M when unsealed | Immeasurable | Irrelevant | Irrelevant

Striking Strength: Small Building Class (Able to hurt Junko Hattori) | Building Class (Destroyed the arm of a 30 meters tall robot with sheer strength, one-shot Mister X after regaining his magic) | At least Building Class | Universe Class+ | At least Small Building Class, likely Building Class when sealed, Universe Class+ when unsealed | High Hyperverse Class | Outerverse Class | High Outerverse Class

Durability: Small Building level (Tanked the power of his own explosions) | Building level (Caught Act 4 Hiroshi Miwa's punch) | At least Building level (Completely unaffected by Act 5 Hiroshi's attacks), Universe level+ with Peterhausen's protection (Survived his own explosion) | Universe level+ (Took hits from an Awakened Demon King like Zero) | At least Small Building level, likely Building level when sealed (Stated Act 10 Junko can harm him, but it's unclear wherever she would need the Sword of Sohaya to do so), Universe level+ when unsealed (Took a barrage of punches from Marine) | High Hyperverse level | Outerverse level | High Outerverse level

Stamina: Akuto possess a high amount of mana within himself, and can gather more mana from his surroundings. It's constantly stated that his Awakened form can continue fighting against Zero for years, and can fight for decades, maybe even centuries, without the need to breathe, sleep or eat. Has infinite amount of mana within the Afterlife, and can create stories for all eternity without ever tiring

Range: Standard melee range, Several meters with magic | Standard melee range, Tens of meters with magic, Kilometers without limiters | Standard melee range, Tens of meters with magic | Standard melee range, Kilometers with magic | Standard melee range, Kilometers with magic | High Hyperversal | Outerversal | High Outerversal

Standard Equipment: None notable

  • Optional Equipment: An incantation gun

Intelligence: Akuto is a brilliant student, having been able to pass the entrance exam of Constant Magic Academy, when it is said that no student had been able to pass it before. Akuto was able to learn Kakei, an extremely difficult technique that took the Headmaster many years to master, in a few minutes, and mastered the Hattori family illusory technique after seeing its functioning. Upon Awakening, Akuto connected his mind directly to the gods, gaining the knowledge of every single action, every single thought, every single emotion any human being had ever have, knowing the entire life of every single individual in the past

Standard Tactics: In Act 1, Akuto primarily relied on his use of explosion magic, but when forced, he was shown to be willing to use his paralyzing and telekinetic techniques | In Act 2, he relied on an incantation gun to home explosive mana bullets to his targets and creating tornadoes to maximize damage. In Act 3, Akuto showed that if his powers were to be nulled, he would focus on hand to hand combat. In Act 4, he would put the opponent through illusions showing them their death so they'll become unable to attack him due to the shock | In Act 5, Akuto mostly focused on combining hand to hand combat with the use of Kakei. In Act 7, he mostly focused on sending armies of Demonic Beasts to fight on his place. In Act 8, he would stroke his opponent with lightnings | In Act 9, Akuto mostly focused on combining hand to hand combat with the use of Kakei | In Act 10, Akuto used his paralyzing and telekinetic techniques to retain and break the limbs of his enemies until they were reduced to a pile of blood and broken bones. In Act 12, against opponents he wants to kill, he'll shrink them to microscopic sizes and seal inside a virtual alternate dimension, meanwhile against opponents he doesn't want to kill, he'll exchange blows with them | In Act 13, Akuto would create stories that counter the reality imposed by others

Weaknesses: Doesn't control his powers, leading him to use more power than normally intended (although he overcame this weakness by the time of Act 4). Akuto dislikes killing his opponents, no matter the reason. Upon realizing the fictitious nature of his existence, he couldn't help but to wish to finish existence, being on a state of depression due to this

Notable Attacks/Techniques:

  • Immortality: After the world was destroyed and Akuto arrived in the afterlife Brave attempted to travel into the past to prevent the world's destruction. He attempted this many times by, amongst others, preventing the development of magic and killing Akuto, but when he returned to the afterlife of the future nothing ever noticeably changed. That was due to The Law of Identity having predetermined the fate of Akuto and the world. No matter what Brave changed in the past, history would always realign itself to keep the end result the same. Akuto could, for example, later on be revived by someone else, as demonstrated in Act 8.
    When Akuto tried to crush the afterlife and by that erase himself, the Law of Identity stopped that as well, as this wasn't an ending it would allow. In conclusion, while one can kill Akuto in the world of the living, sending him to the afterlife and by that winning against him, it will ultimately make no difference for the fate of him or the world. Furthermore, any action that would even destroy his afterlife self would be prevented by The Law of Identity.
  • All Stories: All of existence is stories. From the inside these stories appear to be truth and from the outside to be fiction. Akuto created all stories that can be described. This includes stories with higher dimensions and without, with time and without time, where the occult exists and where it doesn't and all other sorts of different concepts. Some of these stories contain stories themselves and people like Akuto that can freely create stories. These stories can be called stories of higher story density and can form infinite hierarchies.
  • Void Body: The void body Akuto is a state archived during the final ritual with The Law of Identity. That ritual brought both the stories and Akuto's body down to zero and created a void. During this ritual, Akuto and all souls in him are taken into The Law of Identity and together with it they enter the Anti-Universe, the place where all stories end.

Key: Act 1 | Act 2-Act 4 | Act 5-Act 8 | Act 9 (Awakened) | Act 10-Act 12 | Act 13 (Pre-Possibilities Released) | Act 13 (Post-Possibilities Released) | Act 13 (Void Body)

Notes: The Void Body only existed during a very short time during the end of the story and as such not much is known about it.


Notable Victories

Notable Losses

Reinhard Heydrich (Shinza Bansho) Reinhard's Profile (Speed Equalized. Act 1 Akuto and Human Reinhard were used. Both were willing to kill)

Mugman (Cuphead (Verse)) Mugman’s Profile (Speed was Equalized, Act 1 Akuto, and End Game Mugman were used)

Tanjirou (Kimetsu no Yaiba) Tanjirou’s Profile (Act 2 Akuto and Post-Zeroshiki Training Tanjirou were used and speed was equalized)

Inconclusive Battles

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