How do you deal with someone like this?

I've got this dev at my workplace that is terrible to work with, he's 2 main reasons why I say this:
1. He has no clue about team work, every piece of code he writes is written as if he is the only person that has to ever touch that
2. He's overtly protective and opinionated on things that make no sense, they're non standard "rules" that he sets and enforces by replacing others code with his own (often times you see quite large PRs and after inspection you realize he rewrote parts of code to follow his style). These "rules" also take up a really long time to follow and would make any actually experienced developer question this guy's knowledge, one example of this is where he repeats the same code over multiple components for "encapsulation reasons" and God forbid you create a global helper of some sort, he'll straight up remove it the next chance he gets. Another example is that all his components or utilities live inside 1 base directory, so you have roughly 300+ components in a /components directory, all with non standard names so you can't tell which is related to which.

I hate working with this person, it's annoying and it also sucks because he's sort of a more "senior" Dev so managers take his side most of the time.