[HoneyBadger]

I like to make heavy use of Curse and Horror Mark with C'Tis. In the early game, when Marshmasters are harder to afford and less viable, or if you can build a second fort quickly ,and devote it to shamans (I doubt they're capital only), then 10-20+ shamans spamming these spells should have a visible benefit. What C'Tis needs though-as has been mentioned-are troops that don't care about morale. Vine Ogres might work well here.