For some inspiration, perhaps take a look at this? It's a page containing possible specifics for the Celestial Chorus paradigm--the page is a fan-work, so it's not canon for the CC, and it doesn't have spoilers on anything that is. Might give you an inspiration.

Though I guess it depends on if he's actually a holy warrior, or if he just thinks he is: is he more Cecil from FFIV, or Don Quixote? Does he have actual faith in something, or does he just like the image of the paladin? Either is doable in Mage, but obviously that'll change things a bit.