Bugs can be Reported on the Github
There are 5 parts to a Faction
This is saved per World, There is no limit to how many factions there is or how many a mob is in.. everything about this mod can be edited with /Faction in-game or using a NBT editor on the saved file for that world, if no file is found when loading it'll load 4 default factions, Zombie, Skeleton, Illager & Piglin.
For any Entity within a faction (supports multiple at the same time), it'll attack without reason any Entities within an Enemy Faction, however it will NEVER attack any Entities within an Allied Faction.
This mod doesn't work on Entities with Brains, they will be attacked automatically by enemies and the ally system still prevents them attacking allies, and they will not attack enemies automatically. a list of Entities with brains is below (since no Wiki pages does)