In Ninninger, the villains weren't all together like in Ninja Steel. Kyuemon was mostly alone with the grunts and monsters in the series.
Galvanax / Gengetsu Kibaoni
He is the big bad of both series. In Ninja Steel, Galvanax is master warrior of Galaxy Warriors and out to get the Power Stars. He is defeated in first season and does not return in the 'super' season. Gengetsu Kibaoni is the master his underlings try reviving but do not do so until midway through the series. Ariake no Kata is also his wife. They have to gather fear to revive him.
Madame Odius / Kyuemon Shingetsu Kibaoni
Madame Odius is a general but a larger scope villain in Ninja Steel. Kyuemon is the main villain in Ninninger. Kyuemon is male, Kyuemon Izayoi was a ninja who held a huge proficiency in ninjutsu. Kyuemon went astray and betrayed his teacher, ultimately falling to the dark side. Kyuemon is still easily aggravated by flighty or playful persons like his former teacher Yoshitaka and Tsugomori. Madame Odius is sneaky and kidnapped Aidan and took his memories and made the android Aidan to trick Brody.
Ripcon / Raizo Gabi
Raizo Gabi is a crude Spearman who desires conflict so much, he does not wish to be anywhere other than the battlefield. He's also dismissive of anyone he deems lower than his station, such as Kyuemon Izayoi. Ripcon makes fun of Brody and is Galavanax's loyal servant. He is destroyed by the Power Rangers halfway through the first season.
Cosmo Royale/Baron Nero
Unique to Power Rangers, Cosmo Royale uses a costume of a villain of a series that ha syet to be adapted. Baron Nero is an Evil Army Shadow Line general in Toqger. Baron Nero disagrees with his fellow commanders' way of doing things, caring the most about resurrecting his lord and infesting the land, believing it should take priority over keeping the Emperor's future bride putting him at odds with Madame Noir. Cosmo Royale is the host of Galaxy Warriors in Ninja Steel and changes face to emotion, he makes the monsters grow.
Badussa/Ariake no Kata
Ariake No Kata was the last of Kibaoni's generals to be revived by Kyuemon Izayoi in the present day. Ariake is an imperious, shrewish woman who is extremely vain, often using the fear Kyuemon Izayoi gathers as a beauty aid to wipe away her wrinkles so she will remain beautiful when Gengetsu Kibaoni returns. Badussa was a captive of Sledge and becomes Madame Odius' assistant.
Tynamon / Masakage Tsugomori
In Ninja Steel, he is a general who works for Madame Odius and steels Levi's voice. While he seems to be playful, its a cover for his inner darkness and he is wise enough to discover that Kyuemon is just a new member of the team and threatens to kill him if he tries to plot something that is against his master's will. His first act as commander was to create a competition for ninjas to lure in the Ninninger.
Brax / Mangestu Kibaoni
Mangetsu was thought to be the firstborn of Gengetsu Kibaoni and Ariake no Kata. After coming out of his mother, he started stealing snacks from children. Mangetsu pretends to be a buffoon, stealing snacks from children and being a poor warrior and a mama's boy. Brax was a famous fighter in Ninja Steel. He arrived as a guest on the Warrior Dome and starred as a contestant in the latest season of the hit show Galaxy Warriors. As the Ultrazord destroyed him, he called out to Badonna, apologizing for his failure to defeat the Rangers, before being consumed by an explosion.
Lord Draven / Juza Yumihari
Juza Yumihari is a Samurai General in the Kibaoni Army Corps who happens to be the most powerful of the group. He has also led the group for Dinosaur's Lord movie and the Ninnin Girls Vs Boys Final Wars. Juza is tasked for searching for the "Evil Dragon" said to dwell within go to a secret hidden village that only ninjas can reach. He also has threatened the village castle. Lord Draven is the main antagonist of the special episode "Dimensions in Danger" in Power Rangers Super Ninja Steel, who wants to destroy the multiverse. In order to achieve his goal, he has to kidnap Power Rangers throughout the multiverse and has an army of Robo Rangers.