This mod is an encounter type where when you achieve some sort of status as a character, you will be visited by a "champion" of that feat.
Origination of this idea: When you first wear a full suit of a type of armor, a "champion" of that armor type (and appropriately high level) will attack you. (or will be waiting for you somewhere....)
But it could extend to different aspects. When you achieve certain ranks in a guild, a member of an opposing guild will attack you at some point.
Ideally this would extend further to include all the skills and attributes to make it a full system, not just combat based.
These enemies could drop enchanted equipment or an armor/weapon that is 1 level higher than the highest equipped.
This could extend further to a 'revenge' system where when an enemy confronts you, a pop up indicates it's because of a previous incident.
I feel this would add life to the world and add to the sense of progression. The world would be reacting to you.