Akuroninja

Akuroninja is one of the most evil of the Kuroninjas, even though he’s not the most evil. The most evil Kuroninja is Akuma no Kuroninja of Earth 666. Anyway, Akuroninja is from Earth 4.

History
Akuroninja once defeated Lord Nemesis, who had taken over Earth 4. But instead of freeing Earth 4, he took control of Lord Nemesis’ army due to all this power. Then one day, he heard of other universes existing, and decided to take it over.

Kuroninja then heard of Akuroninja, so he and other rangers from different universes began fighting against Akuroninja. The damage to the Multiverse was so large that Kuroninja’s Earth-0 Counterpart had to reset the timeline.

The Ultimate Weapon
But Akuroninja wasn’t done. He sent his enforcers such as ZyuohCrow, DSR, and Phoenix Soldier to defeat Kuroninja, but they all failed. Akuroninja, however, had a secret plan. He got his enforcers’ powerups and combined them with the Neo Cyber Adapter of Cyber Kuroninja, whom he had just killed, to make the Ultimate Weapon. He tried conquering the Multiverse, but was killed on December 26, 2017.

Becoming Overseer Of Darkprism
Akuroninja, however, ended up in Darkprism after dying due to his lawful evil alignment. He rose up to the ranks and became an Overseer.

Later, Akuroninja raided Kuroninja's Dojo during a Christmas party in 2018. He was defeated by Monika and ended up in the Shadow Dimension, where he was found by Akinom.

Perfect Conqueror
Akuroninja then returned to Earth 1 as the Perfect Conqueror, Akinom's puppet king for her plan, known as the Great Salvation. Akuroninja killed Sayori, but was defeated by Kuroninja in his new Sky Armour. Akuroninja and Akinom then disappeared for a while, only to return again. Akuroninja killed Lord Nemesis, betrayed Akinom, and killed Kuroninja, who ended up going to the Nature Dimension.

Akuroninja was then defeated by Kuroninja, who had returned from the Nature Dimension with the help of Sora, the very first Void Ninja.

Return to Earth 4
Akuroninja reformed the Enforcers on Earth 4, but his empire was smaller than before, so he had to put his base on a large island. He was still able to replicate his dimension-travelling technology, and he also learned of Kuroninja's ability of Idolization. Akuroninja sent some of his Enforcers, including the mercenary HurricaneDark, to kidnap Kuroninja and retrieve the Blade of Kings, but Anti-Kuroninja had already captured Kuroninja in a more reckless manner.

Akuroninja found the Blade of Kings and revealed the new power of Metalization, but he also used Force Idolization due to being lawful evil. Kuroninja defeated him using the power of the Legendary 7 Armour.

Trivia

 * Akuroninja and Anti-Kuroninja don’t get along because Anti-Kuroninja wants to be Kuroninja’s archenemy, but Akuroninja is seen as a bigger threat.
 * Akuroninja is a play on the words ”悪" (Aku, meaning “evil” in Japanese), and ”Kuroninja.”
 * Akuroninja used to have a deep voice, but then the highers powers of Earth-0 disapproved of it. Now, Akuroninja sounds just like every other Kuroninja...ok, maybe not KN-5.
 * Akuroninja is the first to win 2 Kuroninja Awards in the same year. He did this during the 2018 Kuroninja Awards where he won for Least Interesting Villain and Worst Kuroninja.
 * Akuroninja is the fourth alternate universe Kuroninja to be revealed. Coincidentally, he is the Kuroninja of Earth 4.