Father Luca Camilleri is a priest from Malta with a history of charitable work around the world.
Luca was born in Malta where he grew up extremely religious. As a result, he possessed a reverence for the skull of Saint Peter which was located in the nearby nunnery. After becoming a priest of the Catholic Church, Luca spent decades doing charitable work around the world including in Africa and South America which he became known for. Due to his history of good works around the world, the Pope gave Luca the title of apostolic protonotary supernumerary and called Luca "a most holy man."
In 2018, after the skull of Saint Peter was stolen, Luca was requested by his village to find the skull and buy it back due to his well-known trustworthiness. Luca was given all the money his village had to buy it back and due to Antonio Miele's disappearance after the skull went missing, it was quickly realized that he was the thief. Luca followed Miele to Seattle, Washington in the United States where he was staying at the Patricia Hotel.
After his arrival at the hotel, Luca bumped into Dean Winchester, but learned that he was too late and Miele had been murdered. Luca discreetly observed the proceedings following the murder and the interest Sam and Dean had in the case. After Dean tripped the fire alarms, Luca snuck into Miele's room and overcome with excitement, knocked Sam out and took the clue. However, Luca was ambushed by Mr. Cromarty outside, knocked unconscious and the paper Sam had found was taken from him.
Luca was found shortly thereafter by the Winchesters who questioned him on his actions. Nursing a bruised head, Luca explained his mission to retrieve the stolen skull and explained how much the relic meant to him. Luca earned the Winchesters' sympathy over his mission which, with his failings, he started to doubt and suggested abandoning to go home. However, the Winchesters, who believed Luca's story and looked up his history online, decided to help Luca retrieve the skull and bring it home.
After leaving the hotel, the Winchesters and Luca tried to determine who had attacked Luca with no luck. However, Luca had memorized the number on the paper he'd taken from Sam which Sam was able to determine was a tracking number for a package sent from Malta five days before. By following the package, the Winchesters and Luca discovered Mr. Cromarty retrieving the skull from a shipping office and followed him to a warehouse where Mr. Cromarty met with Margaret Astor.
As Sam entered the auction to use Luca's money to buy back the skull, Luca remained in the Impala with Dean, listening in through Dean's cellphone. Noticing Dean's worry, Luca reassured Dean that God would assist them, only to be told by Dean that God wouldn't help. Dean explained to Luca that he knew God existed, but also knew that God didn't care about any of them. Luca admitted that he wasn't expecting a miracle, but he did believe that all good things were God's things and that what Sam was doing was a good thing. Luca acknowledged however that what Sam was doing might also be a stupid thing. Hearing that Sam had gotten inside, Dean and Luca departed the Impala for their part of the plan.
In order to take out the sentries guarding the building, Luca approached one man and announced that he was creating a distraction, allowing Dean to choke the man unconscious from behind. Dean ignored Luca's questions about the man's safety and dispatched the other two sentries before heading inside to help Sam. Dean ordered Lucca to remain outside and Luca promised to say a prayer for their safety.
As a firefight raged inside, Luca prayed for strength before heading inside to aid his friends. Luca entered the building as Mr. Cromarty went for Dean as he killed Richard Greenstreet's Bodyguard. As Mr. Cromarty went to shoot Dean, Luca grabbed his arm and struggled for control of the gun. After a brief struggle, Mr. Cromarty shot Luca before turning on Dean, only to be shot dead by Sam.
In the aftermath of the firefight, the Winchesters discovered that Mr. Cromarty's bullet had only just grazed Luca, leaving him relatively unharmed which Luca declared to be a miracle. Luca joined the Winchesters in confronting Richard Greenstreet only to learn that he had lied about having saint's blood in order to get the Winchesters to steal the skull for him. With the criminals defeated, the Winchesters alerted the authorities to arrest Greenstreet and the unconscious sentries while Luca was able to retrieve the skull for his people.
The next morning, Luca was taken to the airport to return to Malta with the skull. While Luca acknowledged that the skull was only "a hunk of bone," he insisted that they all had to have faith in something. Sam asked Luca about his title as an apostolic protonotary supernumery and Luca explained how it was given to him by the Pope for his good work and how the Pope had called him "un uomo santissimo" ("a most holy man"). Realizing that Luca fit the criteria that they were looking for, the Winchesters requested some of Luca's blood which he supplied to them.
Luca was a deeply religious and virtuous man to the point that the Pope himself considered Luca "a most holy man." Luca possessed a deep reverence for the skull of Saint Peter and what it represented, both to himself and his people. While Luca believed in God, he did not believe that God would miraculously intervene in situations. Instead, Luca believed that all good things were God's things. He was also realistic enough to know that a good thing could also be a stupid thing and that "many times they can be the same."
While talking with the Winchesters, Luca expressed a belief that the world is not perfect, but that that fact doesn't excuse bad actions and choices. Instead, Luca believed that one must work to improve things in whatever way they could and that "if good men do good things, it can be better. Every day can get better."
Luca was shown to be a kind, compassionate and brave person. His compassion was so great that he spent decades performing charitable work in impoverished areas of the world that needed his help, work that gained Luca recognition from the Pope himself. During a dangerous gunfight, Luca put himself at risk to save the life of Dean Winchester despite being ordered to stay outside where it was safer.