Not sure if this has been identified yet, but the counterattack granted by the ability "Reprisal" appears to cause the game to hang if it kills the creature that attacked the unit with the enchantment. I was able to finish out the battle with auto-complete, but not by waiting.

As an aside for this ability, the level-up Ability-selection text for reprisal does not adequately indicate what type of ability it is. The text suggests a passive constant ability for the unit selecting the ability, while in practice it is a blessing that can be used on other units every couple turns. The text is misleading and should be revisited.