Dusk is a tank and a offensive spinblocker.
Currently players in pro are using machamps,medichams etc pokes and dusk as a ghost is a good counter against fight/normal ones.
Plus it has Shadow sneak as priority move, and can learn all elemental punches making it a good physical bulk along with tank.
along with that it can learn willo-wisp , a good move to reduce atk stat and give physical dmg to opp. each turn.