source for Sage of Water[]
In the video all the sages look pretty similar so there doesn't seem to be a way to distinguish between them. Instead it was the Ancient Sages which seem to be ghosts.
Clearly doesn't seem to be one of the sages from Ocarina of Time.
"Ganondorf, who had been chosen by the Triforce of Power, did not perish, and managed to kill one of the sages." — Hyrule Historia, pg. 113 does not specify which aspect that sage represented.
What canon source is it that the slain Ancient Sage represented water? Tycio (talk) 03:22, 10 April 2023 (UTC)
The cutscene of Ganondorf being banished takes place shortly after Link arrives in the Arbiter's Grounds. As the Ancient Sages speak, the camera pans to each individually. By process of elimination, each of the original 6 is present except for the sage of water... also he's the one who stabbed Ganondorf, so I suppose Ganondorf wasn't all to happy with him specifically.
See this video at 32:00. Twilight Princess: English Dub - Chapter 8 "The Arbiter's Grounds"VictorV111 (talk) 15:01, 10 April 2023 (UTC)