Yeah, he got picked for his name, or at least the first five letters of it. In truth, his story's pretty plain. In AD 484, the Vandal King (yes, there really were Vandal Kings) Huneric ordered the deaths of Dionysia and Dativa, patrician sisters living in North Africa. It wasn't especially personal -- he ordered all the faithful to be executed. They just got caught up in the dragnet. Dionysia was scourged before she was burned at the stake. Lucky Aunt Dativa was just burned at the stake.
While she was being scourged, Dionysia called on her son Majoricus to keep the faith. The record says that he did, even as he was beaten to death by Huneric's executioners.