What does the power bracer do?

Answer 1

it helps you raise a pokemon's EVs aka effort values which are hidden stats that help it become even more powerful when it levels up if I remember right it makes it so it gives you +4 evs to attack as well as whatever ev's the other pokemon would give you so if say it's a patrat it would give 5 ev's to attack

the evs max out at 255 and for every 4 ev's that stat gets +1 by level 100 so by level 100 a maxed out ev stat gives like +63 to that stat

so let's say normally when fully raised to level 100 your staravia has 200 attack

well if you ev trained it for attack then it would add +63 to it making it 263 a pretty huge difference

also you can only make out 2 ev's so beware of that and choose wisely depending on what you're trying to do with your pokemon