He is in a house in Blackthorn City. :D
There's a man in Fallabur town who will re-teach a Pokemon a move for a heart scale. But you must find a heart scale, they are in several places on the map but are mostly in or near water.
well in pastoria city theres a man in a house that makes your Pokemon remember moves and he ask for a heart scale
How do you fix what part of heart-gold? Man, its getting annoying how unspecific people are these days.
Bring it to the man west of fallabor town and he will teach one of your Pokemon a new move
get an explorer kit from the old man in eterna city and dig up heart scales.
Obtain the "Red Scale" from the Red Gyarados and take it to Mr. Pokemon. (the man you receive the Mystery Egg from at the beginning of the game)After you beat or catched the red gyarados, you get a red scale. You can trade it for a exp share by Mr pokemon!
man who is mr.fuji
A man in Fallarbor trades them to teach one pokemon one move.-Stryker101
To get a heart scale you must either have beaten the eterna gym and gotten the explorer kit from the underground man he is next to the Pokemon center or looked around for it hop this helps :>
You use the explorer kit you got from the old man in eterna city to go underground and mine at the sparkling spots on the walls eventually you will dig up a heart scale
in pastoria city where the man says he is in the middle of the town the building next to him
behind your pokemons