Also, would it be possible to implement something like this:
Avenger level 1 - has one unit from each faction in the list of sworn enemies.
Avenger level 2 - has two units from each faction in the list of sworn enemies.
Avenger level 3 - has three units from each faction in the list of sworn enemies.
Avenger level 4 - has four units from each faction in the list of sworn enemies.
In other words, the list is expanded as the racial skill is leveled up (it can be determined who specifically will be added to the list when leveling up, or it can be done randomly).
Блистает там воздушностью прогалин.
Но между кедров, полных тишиной,
Расщелина по склону ниспадала.
О, никогда под бледною луной
Так пышен не был тот уют лесной...