Ethnic Cleansing

after unlocking a tradition, a court position will be opened. assigned an African with a BBC to this court position.
a casus belli will be unlocked. if this position is filled.
this casus belli can only target a county. and after war no truce will be declared.
after victory is decided. if the attacker won, the culture and religion of the county will be forcefully changed into whatever the culture and religion of the court position. also this will kill everyone in the defender court, replacing it with people from the court position culture and religion.
after this has been resolved the court position will be vacant as he is now the leader of that county and your vassal.
you can then have a character interaction be unlocked to play as him and also change back to your character via a decision.