One of the greatest features of any Pokemon game is the ability to name your Pokemon whatever you want as long as you think it sounds nice. But what if you don't like how the name sounds when it comes out of your mouth, you misspelled it while typing it, or you like the name but it is offensive to someone else?
Do not worry. You can visit a Name Rater and he will help you find the perfect new nickname for the little pocket monsters on your team. Here's how you can change your Pokemon's nickname to Pokemon Brilliant Diamond and Shining Pearl.
The only place you can find the Name Rater is in Eterna City, the location of your second Pokemon gym battle. As soon as you enter the town of Eterna City, head two blocks south of the Pokemon Center, turn right and you will see the Eternal condos next to the Poke Mart. Once you enter the building's lobby, you will see the Name Rater lying on the table to your left. Approach him and he will offer to evaluate the names of your Pokemon.
Then, select the Pokemon in your group or boxes whose nickname you want to change. Regardless of what name your Pokemon has, its species name, or what name you gave it, it will tell you, “That's a decent nickname! But would you like to give it an even better name? What do you say?" Then you can go in and type in whatever name you think is more suitable for your Pokemon than the one you named before seeking the Name Rater's advice.
