I would have to double check academy rules, but arena rules you still go through every step. Normally this doesn't matter much, because a creature can't make a counterstrike from the discard pile. However the skunks ability doesn't list any need to target or be in the same zone as the attacking creature. The only requirement is that the attacker performed a melee attack. Thus, the attacker would receive a stagger condition even if the skunk died.