You can't catch Azelf in Pokemon Heart Gold. Sorry! But you can catch it in Diamond, Pearl or Platinum. Hope this helps!
azelf is at route 23
Only by trade with D/P/Pt.
You can't catch Rotom in heartgold.
nope
catch or defeat palkia and go to lake valor and you Will find azelf
you cant catch him in heartgold you can only get him in soulsilver
you have to go to lake verity cavern and catch it.
You can't catch one.It can only be caught in Pokemon Pearl and Diamond
In HeartGold you can catch Kyogre.
Azelf is found in the Sinnoh Region, in one of the three caves in the middle of the three lakes. (Pokemon Diamond and Pearl). You can catch azelf after you catch the Pokemon Dialga or Palkia. It depends on the type of Pokemon game you have Pearl for Palkia and Diamond for Dialga.It would be best to catch Azelf with an Ultra ball. But if you havent used your master ball yet u can catch Azelf with that. Use Kricketune's false swipe, the use luxray's thunderwave to paralyze it. It took about 10 dusk balls.
After you catch dialga you go to Valor Lake and use surf across it. Then you go in the cavern and azelf in inside it.
You can only catch Vulpix in SoulSilver, not in HeartGold. You can catch it on route 36 and route 37.