When you evolve Vivillon, is the form that you get permenant until you change your region again?

Question

Hi, I just got a shiny scatterbug (thank you based masuda method) and I was wondering if: When you evolve your Vivillon, is the form you get unchangeable, or everytime you chage the region, you will change the form? Is it unable to change form if you got it from a different game (ex: traded to you)

Answer 1

The form of a Vivillon is based on where it was obtained. It is unable to change form if traded to you.

Vivillon has 18 different distinct patterns depending on the set geographic location of its original Trainer's Nintendo 3DS. This form cannot be changed. The pattern of Vivillon encountered within a game is set when the save file is created.
Bred Scatterbug will evolve into Vivillon with the same pattern as that of the breeding player's game, regardless of its parents.

Source: Bulbapedia page for Form Differences