His real name is Giuseppe Oro often called priest Oro and after some time Bishop Oro is a clergymen(that may be a quack). Nowadays he is a bum who makes his money selling indulgences which is how GEO figures out that maybe he is forging the indulgences based on how informally he gives them. Even then the 2 agree to keep it a secret.
Good deeds do good things
One day Deadfish got lost and started sleeping on a bench Bishop Oro seeing Deadfish with seemingly no hope had sympathy for him and took him to his place. As Deadfish woke up Oro appeared to him as a holy man helping him in his time of need and ever since then Oro is a very welcome guess to Deadfishes parties who makes much money from selling exorbitantly priced indulgences to people who believe him and hyper cheap indulgences to those who figured him out. Even then that's generally Oros only source of income.
Adventures of Oro
Oro has weathered many problems from selling forged indulgences since many religious groups see Oros actions as something that tarnishes the churches reputation. Oro many times has had to run from angry mobs. Despite this there were some people that Bishop Oro had to face off with including Bishop Paul who's out to get him for this. Bishop Oro has also been on a treasure hunt for powerful holy artifacts to make his forged indulgence's look realer. Bishop Oro also had a brief stint as a magician but had to face off with some guy named Fabio and his master Atlante the wizard. Oro does know some magic either way
Bishop Oro is generally lazy but kind to the people he trusts. His favorite food is pizza and has eventually became a close ally of lawyer Doug Savage. Bishop Oro in his kind heart has mild guilt for faking indulgences but justifies this by saying he needs the money to live. Bishop Oro hints that at one point he may have been a priest but may have given up on it for certain reasons. Bishop Oro frequently justifies any ridiculous things he does by saying that since he was a part of the church at one point he is god and uses this to frequently be self righteous. He secretly admires ultra religious people since he doesn't have the guts to be one of them. Even them he ups the price on indulgences to them