He he, yes maybe each murder was just the dragonborn trying out a new class
Its just hard to see how a druid or ranger would fit into the murder of a gambler in a major city, where as all the others seem mechanistically easy for a strong dragonborn with some sorcery abilities to carry out. But obviously a young dragonborn may just be a single agent among many serving some greater purpose and perhaps there are some monsters that have similar abilities (eg forest hags seem to).