This mod allows you to steal an enemies vassal if you manage to occupy 75% of the vassals planets during a war.

In the late game, wars often become quite big and quite tedious when you battle against multiple enemies in a federation or an overlord swarm. The win condition of these large scale conflicts is especially gnarly, since you often need to occupy multiple enemies to gain any meaningful reward. This mod tries alleviate this issue by enabling the player to steal enemy vassals through occupation of just the vassal itself and therefore enabling some smaller scale rewards, even if the overall war doesn't end in a total victory.

The war goal doesn't matter, the mod simply checks at the end of a victory or status quo if any subjects have enough occupied planets. You can also lose vassals to the AI if you don't defend them. The vassals always go to the empire with the most occupied planets by him and his subjects. If multiple parties occupie the same amount of planets, the number of occupied systems acts as a tie breaker.