If you are struggling in fights against tough trainers in Pokemon Scarlet and Violet and you want some help/support through the game mechanism, you should try using the item Eviolite which boosts the user’s defense and special defense by 50 percent which could be very helpful in fights. Remember that this item can only be utilized on Pokemon that have the potential to evolve further.
How to Get Eviolite
There are two ways you can get Eviolite in Pokemon Scarlet and Violet:
First Way: You can get Eviolite as many as you want in the post-game as long as you have the money for it.
Second Way: The second way you can get Eviolite in the game is by battling in the southeast of Poco Path Lighthouse called South Province (Area 5) and earning Eviolite free of cost.