You got mystery gift in Pokemon diamond but you don't get anything when you use it with your friendhow to get the stuff from it?
Your friend must have the gift as well.
In order to catch Registeel in Pokemon diamond, you need to have gotten a level 100 Regigias from a mystery event. This mystery event has passed, so you can no longer get Registeel in Pokemon diamond, unless a friend trades you the mystery event Registeel. The only other way to get Registeel is to trade him from Pokemon emerald, ruby, or sapphire.
Errr,Umm..There isn't IQ in Pokemon diamond. There IS IQ in Pokemon mystery dungeon.In Pokemon mystery dungeon, feed you and your buddies gummies that match their type- blue=water royal blue=flying red=fire yellow=electric black=dark clear=ice white=normal purple=dragon pink=physic green=grass .....am i forgetting anything?...