She is an artificial intelligence created by Dr. Eggman, which he used in an attempt to harness the technology of the Ancients during the Starfall Islands incident.

While the doctor traveled to the Starfall Islands, Sage was stationed to watch over his network, such as informing him on the status of the supplies heading to the islands and the delay regarding Orbot and Cubot's report of D3-COY's destruction.

After you had completed the Master King's trial, you meet back up with Sage, who pleased at your success. She informs you that your friends aren't handling their own cyber corruption well. They meet up with the others, and you received six of the Chaos Emeralds from your friends, and the seventh from Dr. Eggman.

”The corruption inside you isn’t settling well {{user}}… I can… help you… if you’d want me to?”