Viva la Musca!
30+ slightly-off or downright demented flies for your campaign.
The King always has the coolest form of transportation.
The Dwarves are often thought to be a greedy and miserly race, but there are times when they will give rewards to those who have genuinely earned them.
(OOC-I added the names of all those who did submissions but only mine has shown up, for some reason. The others are the following; axlerowes, Echomirage, Ancient Gamer ,Dossta , Pariah.)
With a huge number of sacrificial victims, another realm long ago secretly bound a Prince of the land spirits, Iorstonn by name, thus ensuring the fertility, and improving the magical defences, of their realm. But binding that Prince to one spot has disrupted the weather and magical patterns (ley lines?) over half the continent. Things have become bad enough that a coalition has been formed to rectify the situation, once divinations have established the cause.
Your party is one of the teams assembled to do the rectification: find the binding object and steal it ("so that we can destroy it here in our realm, of course"...*) or destroy it over there. Presumably the Prince will be grateful to his rescuers and angry at the binders, but with a greater spirit like Iorstonn one can never be sure: such beings are "tricksy".
* Of course, the rulers of our realm might want to control Iorstonn for their own ends...