Secret Identity Kept Secret

In Super Sentai and Power Rangers, we have known the secret identities of the heroes, the Rangers more than anything, but some remain a mystery. Maybe we were never meant to know. They just are, like Martian Manhunter, he just is.

Shurikenger
Shurikenger was Shurikenger. Everyone tried to discover his secret identity. He even took upon himself to take other people's images to trick the Hurricanger and his enemy. He had sacrificed his own identity to become Shurikenger, he once was a great ninja of the Hayate Way.

Aka Red
We never meant to know his identity, as he was a representative of all Red Warriors, through the 30 years of Super Sentai. He only appeared in Boukenger vs. Super Sentai. For more on him, click here.

Phantom Ranger
The biggest mystery in Power Ranger-dom, the secret identity of the Phantom Ranger. Alex Dodd (Real name is Ali Afshar, who was pretty photogenic himself) provided his voice for eight episodes. Rumors go around that his identity was to be revealed in a third part of "Countdown to Destruction" but budget didn't allow for it. In a rumor that isn't well circulated or accepted, that he was supposed to be Zordon's son, it could be probable as he was said to be from Eltar. I think it is cool we never found out his identity. The UK Power Rangers Annual for 1998 contained the following biographical information on the Phantom Ranger: "This mysterious character embodies the spiritual essence of all Power Rangers, past and present. He arrives and departs in a strange apparition. He is part real, part ghost and never discloses his identity."

Related: Shadows of Aka Red