Diplomacy Hero Trait Tree
I think it would make heroes more varied and interesting if they could level up and be used for diplomatic and espionage purposes. Here are some ideas.
1. Bluffer -Boosts Faction Power score.
2. Envoy - Can move through neutral territory as if he was a caravan.
3. Representative - Can be stationed in neutral and allied players cities where he would provide a small d.cap/gold bonus to both players. Grants player the option to anonymously and quietly slow production in that city by spending gold/d.cap.
4. Ambassador - Further increase bonus from 3, and cause unrest by spending gold/d.cap.