You get it by going to one of the 3 lakes and into the caves.
I think you have to do some stuff before they apear in the caves.
Azelf- Valor Cavern Cave found in center of Valor Lake by Pastoria City and Sunyshore City
Mesprit- Verity Cavern Cave found in center of Verity Lake by Sandgem Town
Uxie- Acuity Cavern Cave found in center of Acuity Lake by Snowpoint City
Hope that helps!! =D
There are no 'Grand Lakes' in Pokemon Diamond and Pearl, but there are the three lakes that have Uxie, Mespirit and Azelf.
You can't catch Azelf in Pokemon Heart Gold. Sorry! But you can catch it in Diamond, Pearl or Platinum. Hope this helps!
You can't catch one.It can only be caught in Pokemon Pearl and Diamond
Migrate it.
Agunomu is not really a pokemon in the English versions of diamond and pearl. It is, however, roughly translated to azelf and azelf is found in one of the three main lakes... I will let you find out which one it is though. :)
You can't, you will need to trade them from Pokemon Diamond, Pearl or Platinum.
Dialga (Diamond Version) Palkia (Pearl Version) Uxie, Mesprit, Azelf Darkrai, Arceus, Shaymin
there are 150 kinds of Pokemon that you can see and/or obtain. Unless you have friend trade you Pokemon that you can only get in pearl to you, you'll never obtain them all. In Pokemon diamond and pearl all you have to do is see the Pokemon and you get its data unlike the older versions where you have to obtain them.
darkrai and arcus
in Pokemon Diamond/Pearl Azelf/Mespirit/Uxie are all found in 1 of the 3 lakes. 3 lakes, 1 of those legendary Pokemon can be obtained there.
Milktank is located in route 209 and 210 in both Diamond and Pearl.
No, you do not need diamond and pearl to obtain all the Pokemon in the national pokedex. You either need to have a friend who has all the older Pokemon, or you could transfer the Pokemon yourself from older games.