[K]

Ethereal, Berserking Elephants are the birthright of the "good" monkey nations. It takes a couple of mages, but the research requirements are low.

With a screen of markata and archers, I think a triple bless rush is doable. The etherealness won't help against the fire bless, but it will help against the regular damage.

Other than that, a Falling Frost or Bladewind spam (with Precision boost) is key.

Remember also that while they can generally school you in the battlefield, you can keep them from massing enough troops to take a fortresses with wise archer use (they take fortress with slaves, which are the worse chaff in the game).

Also, every bless strategy is dependent on Bless. If you can kill their priest one the first turn while defending, you can massacre them rather than them slaughtering you. Considering that they will most likely be using a King of Rain to Bless their troops, a mass of archers on Fire Large Monster or a Gift from Heaven(with precision boost) can remove him pretty well.