Father Juan José Gallego, the exorcist for the archdiocese of Barcelona, Spain, revealed in an interview Monday with El Mundo that the devil's "favorite sin" is pride. During the interview he also covered topics like what goes on during an exorcism and how many languages the evil one speaks.

At the very least, Father Gallego is academically equipped to battle the forces of evil, as he possesses a doctorate in theology from the University of St. Thomas Aquinas in Rome, as well as a degree in Philosophy from the University of Barcelona. according to El Mundo.

Regardless of his educational background, however, during the interview, he admitted casting out demons is "a very unpleasant job" and at first he was "really scared" because the line of work forces him to work close to Satan, according to the National Catholic Register.

He claims Satan can speak in any language and frequently addresses Gallego by name.

"The other day I was doing an exorcism, 'I command you! I order you!' ... and the Evil One, with a loud voice fires back at me: 'Galleeeego, you're over-doooing it.' That shook me," he recalled.

Father Gallego, according to The Washington Times, also gave examples of how people who are possessed "lose consciousness, speak foreign languages, possess strength and are deeply troubled."

"There was a boy whom the demon would set his shirt on fire at night and things like that. He told me what the demons were proposing him to do: If you make a pact with us, you'll never have to go through any more of what you're going through now," he said. 

"I remember another case: a demon-possessed 16-year-old boy with no studies who said to me in perfect Latin: 'I order you never to say the Lord's Prayer again,'" he continued.

He recalled the most terrifying case he worked on involved an Ecuadorian woman. He was called in by her husband, who reported that his wife would lose consciousness and fall to the ground whenever she would see a religious symbol. He claims the woman was unconscious when he entered the house, but when he put on a stole and picked up holy water, the woman awoke and began to crawl along the floor like a snake.

"I threw holy water on her and she writhed as it burned her. Her three-year-old son attempted to approach her and she tried to attack him. We had to take the child away. Then she came at me," he said.

When asked whether the devil laughs, Father Gallego answered that he does, and is in fact quite sarcastic. "The devil is completely embittered," he said.

Despite all the trouble and mayhem the devil causes, Father Gallego revealed that devil gets the greatest amount of satisfaction from "making people believe he doesn't exist."