My own preference for Spirits ItNW would be give them all Vulnerabilities or Allergies. Knowledge and Preparation pay!
Fire beats Grass, Water beats Fire, Rock beats Water... or wait, was that the other way around... and what beats Psy... is that even a type... and what the hell is Psyduck....
Anyway, give mundanes something to bypass ItNW that isn't great, but okay. Neijia kind of does that but not really. It does for Sammies with high enough Unarmed combat pools that they'll pick up some net hits to raise the DV and chip away at a Spirit. But a burst fire weapon with explosive rounds would also chip away at most Spirits.