Mods that change world generation or unit data can break older save files. Start a "New Game" when installing major overhauls.
CK3 is already about power, but the "Strive for Power" modding community takes the viciousness to 11, focusing on the physical and psychological toll of conquest. strive for power conquest mods
: Click "Apply" and wait for the completion popup before restarting. Community & Resources Mods that change world generation or unit data