He gives a smiling nod, acknowledging Gaav's word, and says, "I understand he was very literally a holy terror in his day, and Iago-san has a lot of respect for that person.* And he reminds me of Rezo before he was eaten, and..." he rubs the back of his neck in embarrassed recognition of his own issues, "he needs a priest more badly than anyone I've ever seen, ne. One separate from his own religion, the worms at whose heart he knew well.**"
Xel presses the pointy bone of his cheek into Gaav's wrist, and looks up at him with a smile. "Aa. Now what, Maryuu-ou?"
* Ie: the holy terror. Cesare seems to automatically hate anyone from Venice, so he and Iago have spent most of their time together in chilly politeness that makes Xel want to slam heads together.
** Xel's opinions aren't directed at any modern form of Christianity. He's talking about a corrupt and decadent court that assumed the mantle of organized religion, not the real thing. :)