Need a Last Name from a Catholic Saint

I have a character who was abandoned at a Catholic church at a young age. Rather than being given over to the state, he is taken in by the Father and raised at the church. He is devoted to the Father, and he works in the church as a youth. I would like his last name to be the name of the church, and am looking for some Catholic saints’ names as options. I don’t want the name to be too long - one or two syllables should do it.

His first name is [name_m]Cain[/name_m]. I know it sounds quite angsty and dramatic, but it’s for a reason. The name was given to him by his mother, a violent madwoman, because he was born with a red mark in his eye, and she believed he was cursed.

Names I have considered:

[name_m]Cain[/name_m] St. [name_u]James[/name_u] - I am too reminded of [name_f]Rebecca[/name_f] St. [name_u]James[/name_u], so this one is tonally jarring.
[name_m]Cain[/name_m] St. [name_m]John[/name_m] - I like the simplicity, but it’s so common that it feels like it’s missing any deeper meaning.
[name_m]Cain[/name_m] St. [name_m]Raphael[/name_m] - I like the moody vibe, but I feel like [name_m]Raphael[/name_m] is a little too long.
[name_m]Cain[/name_m] St. [name_u]Clare[/name_u] - I don’t know why I keep coming back to this one, but it seems to have the best flow.
[name_m]Cain[/name_m] St. [name_u]Francis[/name_u] - I feel like this one is too soft.

I want it to be one of those names that has positive associations for people of the faith, but that feels a little dark or gothic to people who don’t know the history or associations, if that makes any sense.

Suggestions welcome!

I’m thinking about using St. [name_m]Ambrose[/name_m] - patron saint of beekeepers, beggars, learners. It means “immortal one,” and even though the character is not immortal, I still like the implications of otherness. Any thoughts?

[name_m]Cain[/name_m] St [name_m]Ambrose[/name_m] seems a little complicated for a name, but I can see why you like it. I agree St [name_u]Clare[/name_u] sounds great! Or maybe simply St [name_m]Paul[/name_m]?