Really vrasnam. Diplomacy in Civ 4 was what religion did you go. Watching quill18's lets play every relation was determined by religion until the industrial era at least.
Apparently each leader in Civ 6 has their own agenda which is public. Cleopatra apparently values military power. They also have a random hidden agenda. You can find that out by gossip which is proto-espionage you get by having an embassy or trade route. There is also surprise or justified war. A justified war gives you less warmonger penalty. This sounds like part of the rising tide system. Each trait there gave something the AI valued including the unique ones.
Apparently each leader in Civ 6 has their own agenda which is public. Cleopatra apparently values military power. They also have a random hidden agenda. You can find that out by gossip which is proto-espionage you get by having an embassy or trade route. There is also surprise or justified war. A justified war gives you less warmonger penalty. This sounds like part of the rising tide system. Each trait there gave something the AI valued including the unique ones.