I've also found that the Infernal Civ's start can be very sluggish if you only have the techs Agric, Ancient Chants, Mysticism, Philosophy, Way of the Wicked. Generally, since the civ that spawned Hyborem has so much research, they can find extra techs much quicker. So I generally try to research Corruption of the Spirit up to 1 turn before its completed (in case I get rushed and can't defend adequately) and then Proceed to get Education, Priesthood, and likely Exploration.