Since these crimson ideas seem to be hot right now, i'll add my ideas to the
soup:
As crimsons used to have the weaponsmith subguild back then, it could be
interesting that crimsons could craft their own shield. Killing preset
monsters you could find parts that you could then add to your shield, giving
it various bonuses (different weight, better damage resistance, some stats),
working a sort of a quest system for the guild. Maybe some sword or polearm
could also be coded this way, giving the guild some spice.