Ive been wondering, what would one qualify as a 10p year quest? It's been stated to be the most difficult of all pursuable quests(correct me if I'm wrong though).
Come to think of it. The war threat far exceeds any legitimate threat a 100 year quest could hope to bombard our heroes with.
If it's an organization or person or monster that needs to be taken care of, then I'm pretty sure that even g. Serena could pose a larger threat. I mean, if we're using g. Serena as a yardstick for deadly adversaries they may face, I'm pretty confident that any threat can be lucky to just measure up to Serena, given that he was already absurdly powerful(No way will a threat greater than the 12 exist).
Perhaps it's a political, economic concern that's intertwined with an evil(physical) that needs to be eliminated?