as the guild quest is about to change to a basic daily quest. why not add a new monthly quest or weekly quest for the guilds to do ie
as a guild collective you find x amount of adventures, and have to do so many of these adventures, say total off 100 adventures of some sort including the co-ops to get a extra reward, 500 a bigger reward, 1000 adventures even bigger reward
it will get guilds working together more and will also use up some of these adventures that never get used and just sit there in star menu
kingfisher11
guild ---- north union traders (NUTS)