trupheus I was thinking more like the dragon causes all kingdoms to have debuff productions, and every tick it randomly attacks a portion of kingdoms (you'd get a news alert of the attack, resulting in some peasants and buildings destruction).
Then as everyone sends their armies to attack, we could record how many hit points everyone kills. Then once the dragon is killed the people that attacked could get a proportional cut of the loot based on how much they attacked.
For the loot we could do something like just give the dragon set amounts of resource, 10 million gp or something, that then gets distributed on its death. Or we could do loot boxes that are prepacked with loot and you get a different box depending on how much damage you do to the dragon, have 4 or 5 tiers of loot box or something.
We could do different kinds of dragons too, like maybe a magical dragon that kills wizards and schools and drops MP when it dies, maybe it randomly casts some offensive spells on kingdoms each tick while it lives.
Maybe we could tie this in with the province buffing item, like whichever province damages the dragon the most gets some magic sigil that buffs them for a week or two.