Stellar Sage Mode

Stellar Sage Mode was first expressed in Reiko. It combines aspects of Sage Mode and Star Chakra Mode.

Attaining Stellar Sage Mode
Since Reiko is the first user, nothing is known on how to gain it. Sumaru, Reiko's father, may or may not have been able to use it. Reiko states that it is similar to 's Nine-Tails Chakra Mode enhanced with sage chakra although fundamentally different.

Appearance
Only Reiko can access Stellar Sage Mode. Her clothes change into a haori with five-pointed stars around the collar. On the back, the kanji for Sage of the Heavens is inscribed. It is unknown if the halo around Reiko's head is unique or normal and it is also unknown whether two-toned eyes are unique or normal.

Level 1
Unlike Star Chakra Mode, Stellar Sage Mode gives the user angelic wings which are permanent. Reiko prefers to keep her wings folded since it interferes with her style of fighting. It grants the user all five basic nature transformations including Yin, Yang and Yin-Yang Releases. It is powerful enough to go toe-to-toe with the Yochigan's Clairvoyance Burst Mode.

Level 2: Universal Stellar Sage Mode
After receiving forbidden knowledge from the Library of Decease, Reiko awakened a second level of Stellar Sage Mode, called. All noticeable signs of Stellar Sage Mode is now gone, except for the clothing and Reiko's two-toned eyes. Reiko has access to nine Truth-Seeking Balls, but she almost never uses them.

Trivia

 * Although I labeled it as free use, the character will have to be able to naturally generate star chakra and know how to enter Sage Mode. Other than that, you're free to go!