Rauru

Rauru is a wise old man and one of the seven sages who appears in The Legend of Zelda: Ocarina of Time. Rauru is specifically known as the Sage of Light, and he helps Link throughout his journey. Some background information on Rauru is revealed in the book Hyrule Historia, such as Kaepora Gaebora being an alternate form of his, and it also reveals that he designed the Temple of Time.

Rauru shares a name with a town in Zelda II: The Adventure of Link, similar to the other sages. In The Legend of Zelda: Breath of the Wild, Rauru's name is featured in one of the locations, Rauru Hillside.

The Legend of Zelda: Ocarina of Time
In The Legend of Zelda: Ocarina of Time, Rauru is the first person whom Link meets after being sealed in the Sacred Realm for seven years. Rauru reveals to Link that after the Sacred Realm was opened, Ganondorf sneaked in and attempted to steal the Triforce, but he only acquired the Triforce of Power piece, as power was the most desirable to Ganondorf. Rauru tells Link to awaken the other five sages, as their power is also necessary to stop Ganondorf. Just before Link re-enters into the world, Rauru lends his power to Link in the form of the Light Medallion.

Once Link has awakened every sage, Rauru telepathically contacts Link to inform him that someone is waiting for him at the Temple of Time. There, Link finds Sheik, who reveals herself to be Princess Zelda shortly before being kidnapped by Ganondorf. After this occurs, Rauru tells Link to go to Ganon's Tower, where he and the other sages form a bridge, allowing Link to enter the location.

The Legend of Zelda: The Wind Waker
In The Legend of Zelda: The Wind Waker, Rauru makes a cameo appearance on a stained glass window in the basement of Hyrule Castle.