Bluto was a man who worked at the lumbermill and he loved to sail and was friends with Popeye The Sailor and his parents. He is a childhood friend of Popeye's father and he taught Popeye how to be a hero, which helped him form the RUC. He also taught Popeye the way of life.
He valued the respect of Popeye's father so much he'll risk his life to do anything from stopping people from hurting Popeye to risk his life to save him. He trusted his heart and soul into the entire Popeye family.
One day however after the defeat of Mr. Jap , evil demon Jebidiah attacked and broke Bluto's arm before brainwashing him. Bluto's eyes were bloodshot red and his skin was dark red. He was slowly becoming a demon thanks to Jebidiah's evil powers. Bluto killed his wife and went after his daughter, Olive Oil. He began to rape his own daughter as he was transforming into a demon until Popeye came along and pinned Bluto to the ground.
Not wanting to kill him due to how Bluto respects the entire Popeye family, instead he imprisoned him in a cell and tried to exorcise the demons out of Bluto's body before he became a demon himself.
To this day the exorcism is still ongoing but instead Bluto is becoming much more larger, buffer, and demonic. It is unknown if Popeye will ever bring his fathers friend and his mentor back to normal.