I don't know if my strategies will apply to all characters, but at least with Kano these seem to work. If you tell me who you use I might be able to provide more specific advice.
Nightwolf Shoulder Slam can be punished, it just has a very small window of opportunity. When you expect the Shoulder (which should be hard as most Nightwolf players are very Shoulder-happy) just block and punish. Use wavedashes to bait out the shoulder and punish. Make your single priority to bait out and punish the shoulder. Before long the Nightwolf player will have to change up his strategy, and I promise you the avergae Nightwolf player won't know what to do once he can't Shoulder spam. Home that helps!