I just got the "Sharpened Riposte" mythical gem which increases counterattack damage by +50%. I equipped it on Kro'khad the Throatripper, who I use in Hydra alongside Packmaster, expecting a massive damage boost.

Result: damage didn't increase at all.

Testing the battles in more detail, I realized that the "counterattack" text never triggers when Throatripper counterattacks after Packmaster is attacked, despite Packmaster's passive clearly saying that's a counterattack:

"When attacked, places a [Hex] debuff on the attacker for 1 turn. Ally attacks on targets under a [Hex] debuff placed by this Champion deal 20% more damage. When this Champion is attacked, all ally Terrorbeasts, Goremasks, Hound Spawns, Hellfangs, Fellhounds, Stitched Beasts, and Kro'khad the Throatrippers will counterattack. "

Apparently that means any effects that boost counterattacks don't count for this passive.

This is a big oversight, please fix.