Hydra’s third trait reads “All enemies take 3 damage when dealing skull damage”. In practice, whenever Hydra takes skull damage, this effect triggers.
Does it make more sense for the effect to occur whenever Hydra deals skull damage, though? Only one troop executes the attack when skulls are matched, so why would everyone hanging back take damage?
Am I overthinking this?
(Unfortunately, I can’t test this easily to confirm what I think was happening in a PVP match. The seventh Wild Plains challenge only gives Hydra two traits.)