Second game I got a draw but still couldn't beat his blocks - ward / regen again and the ability that acts like an oath stone but the can still move makes for a very difficult and frustrating game
The oath stone like thing doesnt let the demon player keep his rank bonus. Just denies you the flank bonus.
So flank him with normal guys and you will win. Plague bearers suck in combat, they just dont die.
Sounds like he only had 4 units on the table. Shouldn't be to hard to flank.