writing this section for those who lack explanation or don't see any UFO invasions until later in the game. This mod works in the following way:

1. Allows barbarians to spawn UFOs and alien infiltrators as scout units.
2. Apply a -25 penalty for loyalty to UFOs throughout the map. (Duplicate possible)

Chilled UFOs only inflict a -25 loyalty penalty. With the exception of a few unstable civilizations, they can't have much of an impact on later factions. But things are different if the barbarians spawn multiple UFOs. The loyalty penalty they radiate is cumulative, and eventually, hundreds of thousands of loyalty drops occur in the capitals of all civilizations.

As a result, there will be uprisings in every civilized city on the map.