I have a... Troubling question

[Discantdecai]

Let's say hypothetically I just got 4 badges on one region X, I now have the power to travel between regions, right? All good so far BUT...

But what if I travel to a region Y and come back with said region starter and use it on my initial region (Region X) team what would happen when I go back to the region Y where I "borrowed" the starter from?

Would I be softlocked for over leveling my starter?

 

[Munya]

If you overlevel in a region you have a higher level cap in and go back to a region with a lower level cap that pokemon will indeed not be usable in battle without it fainting itself.  You won't be softlocked cause you can always get another pokemon, you aren't required to use your starter.