Did something go awry with the Slaying Axe card in AD6? Most of the other "slaying" cards are your standard "if not proficient with weapons, the difficulty to complete this check is increased by 4", apart from the Slaying Axe, which states "if proficient with weapons, the difficulty to complete this check is increased by 4", which seems a bit counter-intuitive, and against the idea of the card.
Was this intentional?