Demon invasion.

I'm leveling up one hero, there's no mentorship, and I can't venture far from the castle, especially when an Orc shows up; fighting him in open battle is tough. I'll try to gather an army from two cities for another month, plus I'll grab Ash's tear. Then, I'll conquer all the blue factions, and if things go well, Darkness will spawn in the human castle, which will make dealing with Duncan easier.