Aku is an extremely powerful demon lord and the main antagonist of the animated television series, Samurai Jack. He is a secondary player in the second Disney Vs Non Disney Villains War. He is Samurai Jack's arch-nemesis.
Disney vs Non Disney Villains - Part Two
Beginnings and Freedom
Aku was born a human. However, this is only in the literal meaning of the word. Aku was evil to his core, and truly an irredeemable monster among men.
From the age of eighteen, nothing brought Aku more joy than bloodshed. A deadly samurai known throughout Japan, Aku led a band of warriors that rode throughout Asia, spreading death and despair with every swing of their blades.
It was when Aku found himself in uncharted territory that he found his first defeat. He and his men ran into the territory of the demon king, Shendu, uninvited. Irritated by the mortals, Shendu quickly killed them all, engulfing them in a massive storm of fire. Aku felt his skin burn from his body as he died.
The ruthless warlord's soul descended to Hell, where he was to face an eternity of torture for his crimes. Aku experienced three decades of Hell's greatest punishments.
One day, the Nightmare King, a higher up of Hell's demons, was particularly bored. He felt like having some fun with the souls of the damned, and decided to set up a game. He picked a handful of the most fearsome of Hell's residents, Aku among them, and had them fight in a tournament, the winner of which would get a prize in the form of a second chance at life.
Aku was desperate, he wanted nothing more than to escape Hell. He accepted the Nightmare King's challenge.
The tournament was no cake walk, every other fighter was just as desperate to escape Hell as he was, but Aku cut down all of them. He was the last man standing before the Nightmare King. He had won.
As the Nightmare King began to congratulate Aku, Aku's mind began to stir. This was only a second chance at life. When that was done, he'd simply return to his eternity of torture. Aku stared the Nightmare King in the eye, and refused his prize. He then lunged at the demon.
Aku then decided that rather than live only to die and return again, he'd destroy the Nightmare King and take his place as a high official in Hell. Surprisingly, Aku fought very well, and did a number on the King. But, before Aku could end the battle, the true lord of Hell intervened.
Chernabog was infuriated. The Nightmare King organized this tournmaent without his permission. Chernabog was prepared to severely punish the King, until he saw that Aku did it for him.
Impressed, Chernabog offered Aku a position as one of Hell's demon tormentors, a job he gladly accepted. Chernabog also then demoted the Nightmare King as punishment, which began the King's grudge aganist Chernabog.
Chernabog, as initiation for his new tormentor, used his powers to turn him into a demon spirit. Aku took the form that you see him in today, and happily began his job as one of Hell's tormentors.
A few centuries passed until Aku grew weary of his new occupation. He lusted for Chernabog's throne as Hell's king and challenged him for it. Sadly Aku was no match for the deomn king, who bested Aku and sealed him away in a plant on the surface world. Aku would remain impriosned for centuries. Only a particular dark spell could free him...
Shortly after Eris steals a powerful book of spells from John Silver, she joins her powers with the dark magics of the Incan sorcerer, Tzekel Khan. Together, they free Aku, ready "to once again smite the world as he did in days long past."
Though Eris, still furious with Hades, wants Aku to join her in a seige againt the underworld, Aku thinks it far wiser to eliminate Hades' followers one by one. Therefore, he chooses Hades' river guardian, Nessus, as his first target. Aku travels to the Great River and demands that Nessus surrender, but the mighty river guardian laughs at the demon lord. Enraged, Aku injures Nessus with a powerful blast from his eyes, but Nessus does not fall. Aku then transforms into a gorilla, and pummels Nessus into submission.
Eris and Aku then put their next part of the plan into action: attacking another of Hades' minions, the Father of all Monsters, Typhon. Aku relishes the chance to "show the world who is master". He confronts the giant creature, and calls forth a powerful burst of lightning. Typhon survives the blow, blasting Aku with dark energy while Aku is busy gloating. This injury only serves to infuriate Aku, who retalliates with a powerful blast, sending Typhon flying against a mountain. Typhon grabs the mountain and attempts to crush his enemy. Aku, however, blasts Typhon's feet, causing the monster to drop the mountain on top of himself, killing him. Aku then delights himself in burning down the nearby villages. When he returns to inform Eris of his success, he meets the alliance's newest ally, Discord.
Aku sends his most trusted disciple, Demongo, to steal souls from the River Styx, in order to build an army that will serve the faction. But Demongo fails, thanks to Pain and Panic and Chaos. Once the minion reports to Aku, the demon lord executes his pleading disciple by crushing him in his fist.
Defeat at the Battle of the Underworld
Aku ultimately joins Eris and her followers in an attack on the Underworld itself. Pain and Panic attack him with a flurry of arrows, but Aku absorbs them, uninjured. He then sends the arrows flying at Hades, but Hades evades and melts them. Enraged, Aku then personally battles Hades. Hades burns a gash in Aku, seemingly defeating him, and leaves him to die. But Aku transforms into a giant scorpion and attacks Hades while the god of the dead gloats. Hades counters, using a salvo of fire to knock Aku from his perch. Aku falls into the pit of Tartarus.
Disney vs Non Disney Villains - Part Three
A New Employer
Spending his time in Tartarus, Aku is suddenly released by Mok, through the sacrifice of the Evil Manta. Aku is more happy to serve him, thus he joins his alliance, after his previous was destroyed by Hades. Later, Aku sends Skulker, also one of the survival members of Eris' alliance, to advertize a combat fight against the "Anti-Acolyte", Yono. He, thus, rallies upon a bunch of bounty hunters to deal with the monkey. When the hunters fail, Aku arrives personally to finish the job. Even though, Yono transforms into a massive stone gollem, Aku takes it easily and destroys the gollem, with a blast of his eye-beams, seemingly killing Yono.
Restoring an Evil Spirit
Later, Aku is confronted the spirit of Wuya. The latter one desires a human body at all cost. Aku agrees, with the term of joining Mok's alliance. The hesitated Wuya then agrees to his offer and Aku is more happy to offer her a human host.
Non Disney Villains Tournament
Demon Lord of Darkness
As part of the Four Eastern Demons, Aku meets up with his allies - Tengu Shredder, Wuya, and Shendu - along with their many apprentices. When Chase Young wants a mission, Aku forces him to bring along his personal apprentice, Scorpion. Chase slays his foes, but Scorpion dies in the fray (under mysterious circumstances). Unfortunately for Aku, an attempt to free him goes awry when Rothbart, leader of the sorcerer's society, kills the Foot Mystics. Aku thus sends out Chase Young and Drago to eliminate a member of the sorcerer's society. They only manage to finish off the lieutenants of the Wicked Witch of the West.
Free at Last
Fortunately for Aku, Unalaq manages to free him and the remaining Eastern demons.