I've created some NPCs that I'd like to have stalking the player when they become a vampire (or preferably after they have 100 necks bitten)

I'm confused with how 'Thugs' for example are utilized for ambushing the player after they steal something from certain NPCs.

If you can help me out I'd appreciate it. Thanks.

Possible to start an invisible quest and use quest stages, as well as the code to make Actors aggressive to handle this?