Petronicus is the younger of two sons. Born and raised in East Rikkan the family lived by his father's trade business that ran along the Adivian River.
Being an unusually smart child his father quickly realized the value of having his son work in the family business. When he realized that Petronicus was better at numbers he quickly passed on the book keeping responsibilities as well. Although he helped his father and older brother Petronicus knew that a merchant's life was not his fate. Seeing wizards perform magic, be it for his father's business or entertainment for a fair, had ignited a desire in him that would not be extinguished. Finally realizing that his son's talents and passion were being wasted Petronicus was sent to study at the Arcanamirium in Absalom at the age of 17.
It was at the Arcanamirium, in Absalom that Petronicus learned of the deep love he has for magic. So much so that he secretly began to worship Nethys instead of Asmodeous. Although, being a proper Chelaxian, he continues to publicly worship Asmodeous.
After his three years of study Petronicus was able to graduate and come back home a mage. The influence of his father's business had unconsciously led him to pursue the school of transmutation. Changing one thing into another would only benefit his father's business and benefit the family, whereas summoning devils was only a hassle in his mind.
It was on his return home that Petronicus learned of the disappearance of his older brother. Apparently his older brother had been escorting some cargo to Westcrown and never came home. Investigation revealed nothing. Apparently there was no record of the cargo or his brother ever entering Westcrown. Convinced that something happened to his brother Petronicus has moved to Westcrown to investigate himself. More than familiar with the Chelaxian ways, and more importantly the Westcrown ways, he has set himself up as a merchant in Westcrown. He is convinced that something happened to his brother and that it is related to the criminal organizations.