Origins
The Celestis were the Celestial Intervention Agency, but due to The War they removed themselves from the universe in order to attempt to escape the temporal damage.
Appearance
The Celestis removed themselves from history and detached themselves from the physical plain of existence, making themselves ideas, and thus harder to destroy (harder than a physical body tied down to the time lines).
They inhabit a world outside the normal space time called Mictlan, a place that most probably was constructed using the Matrix. It exists outside the physical universe.
==Celestis Position on The War]] The members of the Celestis were split on who to support during the War; either the Time Lords or The Enemy.