Father Ramon is the reformed vampire support group's spiritual advisor. Nina characterizes him as "a decent man" (3.14) and gives us this description: "With his solid build, shaggy gray hair, and soft brown eyes, he looks like an elderly Labrador, seasoned and weary but not disillusioned" (3.14). Pro tip: Being described as a Labrador is pretty much never a bad thing.
He has a big heart, but he's also a softie. Father Ramon befriended Sanford after Maud died, and he counseled Sanford to end Casimir's punishment underground. We have to wonder if he's become the group's shepherd out of guilt for his role in increasing their numbers.
Father Ramon tries to keep their little group on track to lead a moral existence, really he does. When Horace wonders about whether it would be ethical to bite someone who wanted to become a vampire, Father Ramon informed him "that on no account should such a perverse desire be indulged […] Fangseeker was clearly unhinged, and to take advantage of someone with a psychiatric illness would be inexcusable" (4.71). Without any blood lust to blind him, Father Ramon can see situations more clearly.
Don't mistake this mild-mannered Catholic priest for a pushover, though. He's lived through a lot. So when Nina worries on their road trip that playing music will keep him awake, he reassures her: "I can sleep through anything. I've slept in puddles. I've slept beside the worlds noisiest two-stroke engine […] when I was doing mission work" (7.73-75). His other adventures include an " eventful youth, […] gunfire during a funeral, […] floods in a slum, or how he once had to perform an exorcism" (7.75). He might be moral, but dude is definitely not mild.
In fact, Nina hypothesizes that Father Ramon helps their group precisely because he has an adventurous past: "I wondered if the excitement of his early years in South American had given him a daredevil streak. I wondered if ordinary parish work was becoming a bit of a bore" (9.53). We wonder, too, Nina.
When Barry and Dermid get a hold of Father Ramon and dose him with tranquilizers, he's able to stay awake for long enough to hear the details of their plan—he knows his life is in danger. He can't move because of the drugs, but as soon as he's rescued, he's eager to make a plan to save Reuben.
This leads to Father Ramon stating that he's going to make an anonymous call to the police, hoping to get them to intervene and save Reuben. Why? He explains: "I have to do it […] I have to do something. Because if I don't, I won't be able to live with myself" (18.113). Way to show some backbone, man. Father Ramon's compassion and courage help keep the group together, that's for sure—he's the leader this motley crew needs.