Lothor

Lothor was once Kiya, a student at the Wind Ninja Academy. He was discovered using dark ninja magic  by his twin  brother , Kanoi, and defeated in battle by Cam, who had travelled to the past  to retrieve  a power  source . Kiya denounced the ways of the academy, and took on a new name - Lothor, just before being banished into space by the Sensei.

After amassing enough forces and gaining enough power, he returned to exact vengeance on the planet which had shunned him. He began by destroying the Wind Ninja Academy and battling the Wind Rangers.

After discovering the location of the Abyss of Evil, Lothor captured all of the Ranger powers, becoming nearly unstoppable. Using their inner ninja powers, the Wind Rangers managed  to defeat Lothor and knocked him into the abyss.