I dont understand

So i dont understand how these items work example : the sturdy staff affects the dark and kingdom faction , The sword affects the technological society faction , and amulet of swiftness affects the forest faction . And i know with every upgrade for its rarity it addes 1 faction from common and adds another 1 for rare and another one for epic but what i dont understand is how could i know which faction would i get when i upgrade the item ?

Is it the same for every item every time ? I want the sword to affect dark domian when i upgrade it to epic but i dont know what i would get the same is for the amulet for swifteness amd something else at legendary rarity would it affect all factions or what ??