Akuroninja

Akuroninja is Kuroninja's lookalike and the supreme leader of Earth-4. He is a ruthless dictator who will betray almost anyone to get what he wants.

Biography
Akuroninja somehow became the evil ruler of Earth-4, with his team of evil rangers known as Enforcers. However, this made him bored. He then learned about his ability to travel to other dimensions, and then he created some gear that could help him travel to other dimensions easily. This made him an even deadlier opponent than Anti-Kuroninja.

Behind the scenes
Akuroninja's name is a play on the words "Aku (evil)" and Kuroninja.

It could also refer to "Aka (red)," because of the red accents of Akuroninja'a suit.