I don't know Japanese so the lines below are auto-translated.

The sentences you need to speak (if you are cast) will be all of the monk_rant voicelines. You can find them here.

Here's a Youtube Video with of all his voicelines, incluidng timestamp to the monk_rant voicelines.

You are encouraged to re-write sentences, however stick close to the English originals! Sadly, the translator cannot do that and when I translate it back a lot of lines sound too different.

Audition lines (English original):

1. My power was lost in places which were not mine. Affliction besought me, and the merciless ones attacked me without cause.
2. Thy will be done, Oh Light of Lights. I bless the glory of thy greatness all the day and through the darkness of this night.
   
3. I have been laid down in a pit of darknesses and the shadow of death. And thy anger has pressed down upon me; and all thy cares have come down upon me. And from this bed I cry out for the kindling of thy Light!