Where is the name changer in pokemon diamond? well i know where he is (eterna city)

Question

but when i tell him to rate the name thats all he does. he doesn't let me change my name. why

Answer 1

The pokemon name changer will not change any pokemon's name if it was not originally caught by you. If you bring him a traded pokemon, he will only rate it.

Answer 2

He will only let you change the names of pokemon that you have caught on your own game and nicknamed. Traded poekmon or magrated pokemon with nicknames can not be changed.