The process when a group forcibly removes another group is called

Ethnic cleansing

Ethnic cleansing is the mass evacuation or murdering of the people of a species targeted ethnic or religious group in a society. One of the most famous examples of ethnic cleansing is How the Nazi forces expulsed and committed genocide against the Jewish and other unwanted minorities during the Holocaust.

Complementary goods. they go together, thats why one price increase and the others demand increases