Festival of Wolves is intended for a group of four to six Dragon Age characters with a decent mix of abilities to handle the various scenes – combat, exploration and roleplaying – in this adventure. It can work for larger or smaller groups, or different balances of abilities, with some modification.
A number of alternatives exist to making the characters work for the merchant, which is the easiest way to get the characters involved. The city of Highever is a large one and holds within it many important groups and individuals for which the characters could work, all of which would have clear motives for rooting out the Custodians. The characters could just as easily be caught up in these events without being employed by the merchant or other party, instead choosing to undermine the Custodians for any number of reasons ranging from potential reward or moral justification. If the characters are from Highever, it is quite possible that one of their friends or family members has joined the Custodians of the Wolf, thus giving the characters a personal stake in the adventure.