Villains who have taken to stalking a particular character or group, whether the motive is murderous or obsessive (often it is both). A villain who stalks will usually not attack their target on sight; on the contrary, a stalker will often spend a prolonged time observing their target before they even reveal themselves, let alone cause harm. They search for the opponents or anything that is important to them, or make threats against the victim if they don't do what the stalker wants (namely reporting their stalking behavior to the police or authorities). Or they keep contacting and trying to interact with the opponents who have made it clear they want the villain to leave them alone, and the stalker won't take no for an answer and doesn't respect their wishes and keeps pressing, badgering, shadowing, following the victim in various unwanted ways et al. Of course, the act of stalking in itself can be considered psychological abuse.