Cebas was not always who he is now. Originally, he was a young and clever general by the name of Dartien who worked in the service of a great Warlord. The great Warlord had only one goal in mind - take over all the land in the human continent and declare himself King. True, there already was a King of the kingdom, but that did not deter the Warlord in the slightest. Dartien was his top general, and lead many ruthless campaigns against the people of the country, burning and pillaging as he went. He refused to kill children and unarmed women, despite the Warlord's heckling. He saw little glory in what he did, but it was a job, and for his service he was offered gold and the title of Lord, with land of his own. That draw was enough to commit Dartien to his goal, and he killed and intimidated many people over the course of his service.
He and the Walord had many victories, and eventually, they made plans to march on the Capital. The Warlord demanded a celebration in honour of his great conquest. A great feast was prepared in their encampment on the edge of the capital. The Warlord was a devout worshiper of Gruumsh, and the feast had many prayers to the One-Eyed god and ended with the sacrifice of a young girl that the soldiers had captured from a dairy farm not far from their current location. The Warlord had grown fond of Dartien, and treated him like a son in many respects. He passed the young man the knife and asked him to kill her, in the honour of Gruumsh. Dartien found that he couldn't do it, and told the Warlord such. The Warlord told him that if he refused to kill her, he would make Dartien take her place on the table. Dartien may have been a fine solider but he was very afraid of death. He asked the Gods to forgive him in his head, and drove the dagger into her heart.
Celebrations broke out, but Dartien felt crippled by guilt and retired to his room. When he woke up, he found a thoughtful servant had provided him with a plate of leftovers from the feast, and a warm tankard of mulled ale. He blearily drank the ale, but quickly felt a stabbing sensation in his stomach. Poison. Many would want to rid the world of a General like himself, in service of what many regarded to be an evil and dangerous man. That was his last thought before he fell into darkness.
Surprisingly, he did not die. He awoke in a dungeon at the feet of a man. He recognized the man to be the King they had been trying to usurp. He clung to the King's robes, and begged for a second chance, but the King ignored him. He demanded the public execution of Dartien to set an example to those who showed sympathy for the Warlord. He ordered Dartien to be sent to the center of the city, where he was to be torn apart by worgs. Dartien died, regretting everything he had ever done, while his body was torn to pieces.
Unsurprisingly, he went to Hell. There he found himself at the feet of Lord Mephistopheles of Hell, who looked less than happy to see him. Weirdly, a shadowy avatar of what seemed to be an old, but strong looking man stood next to him. He appeared kindly, and around his neck was the symbol of a sun. Dartien's shade blinked, for this seemed to be some weak avatar of Pelor. He informed the shade of Dartien that he was too good for Hell, but too Evil for the Upper Planes - but that he was too much of either one to go to the Outlands. Thus, Mephistopheles said, they were sending him back and if he proved himself to be worth the time of the Gods of Good, he would be free from Hell. The devil informed him, however, that if he failed this task he would belong to Mephistopheles. Dartien, hoping to save his soul, agreed to the deal, signing the contract in his shaking hand.
The Avatar of Pelor nodded, and placed his soul into that of an infant - as Dartien's previous body was in separate pieces. The Avatar of Pelor marked the infant with the curling horns, and a pattern of red scars that entwined around his arms, legs, and back to remind the child of where he had come from. With that, the Avatar of Pelor wiped his memories, leaving only shadows of the time when he was Dartien. The whole point of sending him back was so that the boy would choose his own path. He placed the swaddled infant on the doorstop of an inner-city Chapel of Pelor, before vanishing into thin air.
He was taken in by the priests, and adopted by a man by the name of Father Prill, who named the boy after a great warrior-knight called Cebas. He enrolled the boy in religious studies and provided him with a tutor for the art of combat and knighthood. Though many questioned the boy's origin, Father Prill claimed him to be nothing more than his own son, whom he loved dearly. When Cebas was 19, he sent him off with a band of adventurers; a wizard who they called P.P., a fighter or scout of some kind, and a dragonborn by the name of Kapesk. Cebas quickly gravitated towards the leadership of Kepesk, although the dragonborn encouraged him to do things that seemed far removed from what he had been taught in the Church.
Eventually, the influence of his new found friends lead him to be found quite drunk, standing on a table, preaching the virtues of cuttlefish and how the grace of Pelor would save the souls of the newly jack-o-lantern'd. A pair of guards found him, and thought to take him up to a room at the inn so that the boy could sleep it off but when they came to help him walk up the stairs, he resisted and bopped one on the nose. They guards took this as an assault, and drug him off to prison, where he was to be kept for no more than a week. When Cebas sobered up, he was horrified to find himself in jail, and vowed never to drink again, or listen to Kepesk's advice again.