Endurance of the Rooted Tree
FEAT 20 Wholeness of Body
Just as the Vale of Aroden retains light and life despite inhospitable surroundings, you can sustain yourself regardless of your environment. You don't need to eat, drink, or breathe.
In addition, you can cast the Wholeness of Body ki spell almost effortlessly. You can cast it as a free action that triggers at the start of your turn.
Pathfinder #156: The Apocalypse ProphetOGL