Here's my thing:
Leader: Guaman
Trait: Warriors of the Clouds
Cities regenerate Clouds (Fog of War), and if unseen by all players, defensive buildings yield Faith and Food. Enemies adjacent to cities have their Sight reduced, and they become weaker the less they see.
Unique Improvement: Purunmachu
Built on Hills without removing features, unlocked at Masonry and yields +2 Faith. The Purunmachu takes Sight from enemies up to two tiles away; if they cant see at all, they also cant heal.
Unique Warrior: Condor
Faster if unseen at the start of the turn, and regain Movement upon killing an enemy; if the turn ends with the Condor unseen again, he gains XP and Health. Retain this ability on upgrade.