I've been doing a deep-dive into the Werewolves pack lately for my Mishmash Legacy.
I can think of several feasible requirements right off the bat.
The founder/heir must:
*Aspirations x2: Complete (1) Werewolf Initiate plus one of three aspirations: (2) Lone Wolf, Emissary of the Collective, or Wildfang Renegade
*Werewolf Rank: Become an Apex Werewolf
*Werewolf Abilities: Earn at least 15 Werewolf Abilities, including the Immortal Wolf ability
*Wolf B-Gone: The founder and every heir must uncover the recipe Wolf B-Gone, which cures Lycanthropy
@GlazeyLady also created a Werewolf-based Big Dream for her Big Dreams Dynasty, so that could also provide useful reference for possible requirements.