One example could be...
A fight breaks up and, before anything substantial could actually happen, the Knight declares their intention to keep the cute NPC safe.
Both fictionally and mechanically no harm was directed at the NPC. Yet. So the Knight is using the move proactively to prevent any chance of that. On a 10+ they are safe. On a 7-9 they are protected but still in danger. On a 1-6 something that COULD have happened is now actually going to happen. Ouch.
Another example...
The cure NPC is being grossly catcalled and harassed by two big sailors. The Knight disapproves and steps in, acting both physically and verbally as a shield.
Depending on the sailor's reaction the harm to the Knight will probably be Nasty, were harsh words and threatening posturing could put them in a "problematic position"... or maybe a sudden shove could make them lose an important item, or get cornered, or fall on their ass, or whatever else makes sense in the circumstance.
In the same way, harm to the NPC would plausibly be Nasty and look like emotional distress, or rage, or shame, or whatever fits the circumstances and could result in a Nasty Effect :-)