Posted: 10/23/16 11:44 PM
This information is not on the client side, you only have your current standing for a given npc. It's not technically not feasible as we could try to observe faction adjustment when you kill an npc and that way tag a npc to a given faction.
Well even that will be difficult as there is no direct relation between you killing a npc and a faction adjustment event being received so for example, if you kill 3 npcs pretty much at the same time, there is no way to know which one triggered the faction adjustment.
So long story short, I wish but I dont think that's doable.