During the Legendary Great War, there are heroes that missed out to join the 199 Heroes gathered by Aka Red. Notably was Ninjaman ニンジャマン, the Partner of Justice in Kakuranger world. How is it Ninjaman who is a very quirky character not join to help the Earth and other allies to fight the invader? According to biography found on net, "In the finale, after the Youkai are sealed away, Ninjaman is now with his masters and says goodbye to the Kakurangers." So he might be not around Earth or summonable during the battle time. Perhaps one of theories to explained this. In 199 all super sentai team up to battle Zangyack, included also Zuuban from Boukenger team, that many feel not actually a character, Zuuban was a sword tranforming to human sized character helping the Boukenger against villains. Which oftenly compared to the absence of Ninjaman.
He is the pupil of Sanshinshou, the three god generals. A thousand years ago, he was deceived by Daimaou to attack humans and he was imprisoned within a blue pot as punishment. The pot was hurled into space by Daimaou. The bottle returned once the war between the Youkai and the Kakuranger was at full swing. The Kakurangers found the bottle, and Tsuruhime was the only one able to remove the golden hammer from the bottle to break it open. As a ninja master, NinjaMan wields a katana, and has a wide array of ninja-magic skills, including enlargement to aid his mentors in their fights. He has the ability to ride on a cloud called the Kinto Cloud. Whenever a Youkai calls him "Blue Squirt" or insluted in such a manner, he gets angry and transforms into SamuraiMan , who connects his weapon with its sheath to form a powerful javelin. In this state, SamuraiMan creates explosive energy spheres formed from his rage in his ultimate attack, Samurai Rage Bomber. In the finale, after the Youkai were sealed away, Ninjaman was able to go away with his masters and bid goodbye to the Kakuranger. "Partner of Justice, NinjaMan!" from Wikipedia and Supersentai.com database
Ninjaman inside the seal container, a blue pot.
For his punishment, being deceived to attack humans
Transforming to Robo size as Samuraiman
quirky character as well.