Tsukuyomi

Tsukuyomi is a member of the Resistance from the year 2068 and one of the main characters of Kamen Rider Zi-O.

Past
Having no memory of her past, she was taken in by the Resistance and given the name "Tsukuyomi".

In 2068, when Oma Zi-O destroyed most of the Resistance members with minimal effort, Tsukuyomi was saved from being killed when she was pushed into a rift by the captain of the Resistance.

Tsukuyomi later followed Geiz to 2018 to meet Oma Zi-O's past self, Sougo Tokiwa. Unlike Geiz, who intended to kill Sougo to prevent the bad future, Tsukuyomi sought to prevent Sougo from going down the path of becoming a Demon King.

The Birth of Zi-O and Another Build
Tsukuyomi saved Sougo from Geiz and showed him how in 50 years he would become the most evil ruler all of history. Despite this, Sougo still obtains the power of Zi-O from Woz though he declares he will use it to become the most good and beloved overlord in history as opposed to the Demon King.

Unlike Geiz, Tsukuyomi was unconvinced at first that Sougo could become the Demon King. However, after Sougo obtains the power of Zi-O II, Tsukuyomi begins to become more distrustful and wary of Sougo.