Ok this feature really ruins the fun in the game.. So if you denounce a player and declare war after 5 turns you should get a reduction of warmonger penalty.. However you still get denounced by everyone if you declare war this way. Declare Protectorate War only works if you have this casus belli at the moment the Ai declares war at youre city states or ally. If you unlock the casus belli after the AI conquered the city state it doesn't work this is what happend at me: I used formal war (denounced him) and then atacked. wich resulted in everyone denouncing me... Then i lberated my city state and got a reduction in warmongering however everyone is still pissed at me. Conclussion the warmonger penalty for declaring war is to high.