[shatner]

rdonj has a good point, you do sound underprepared. I'm familiar with the MP game overall and the mod nation you're facing, and you're looking at dealing with a larger, wealthier nation which has been on war footing for a long time because of its recent war with Ulm. Plus, it's a safe bet that MA Jomon has been planning for this war for a long time, given Shinuyama and Jomon's proximity. You'll need to be careful how you commit your resources (as well as preserve your income) because a war of attrition does not end well for the smaller nation, especially since 33% of your gem income only came online two turns ago from a couple of globals, while Jomon's gem income has been in place for dozens of turns. The troublesome thing about Tengus is that they're really cheap and really mobile glass cannons. With their negligible protection, anything that does hit them will almost certainly maim or kill them, but Jomon gets 2.5 per air gem and it doesn't take long to move them to the front lines (or to your back lines). Therefore, if a force of tengu capture a province with a decent gem or gold income, or if those tengu hack or zap a handful or troops (especially summons or commanders) then they've already paid for themselves even if they are blown to smithereens immediately thereafter. And if Jomon has even a modest air income, it'll be able to replace lost Tengu numbers quickly and cheaply. This thread has some good advice but the real trick, given the situation you're in, is to surprise your opponent.

Good luck and let us know how it turns out.