In Pokémon Diamond/Pearl/Platinum there is a swarm in Route 228 that you can find wild Beldum. Be prepared, Beldum, along with its evolved forms, are the only non-legendary Pokémon to have a catch rate of 3, which is the lowest possible, making Beldum extremely difficult to capture due to its self-damaging move, Take Down.
Yes you can always go back and fight nascour again in realagam tower and get metagross.
at the giant hall in the swirling grass
You can only catch Vulpix in SoulSilver, not in HeartGold. You can catch it on route 36 and route 37.
you can get celibi on heartgold only from a wi-fi event
sorry, you can't catch them, you have to migrate them from the GBA game Sapphire/Rubymigrate
No,
I suggest using the masterball.
You can't catch Rotom in heartgold.
no you can catch it. However you can trade Pokemon to get geodude and metagross on black and white!
you cant catch him in heartgold you can only get him in soulsilver
Beldum evolves at level 54 to Metang and level 55 to Metagross.^This is incorrect.Beldum evolves at level 20 into Metang. Then it will evolve at level 45 into Metagross.
You can't catch him in HeartGold. Only in SoulSilver. In HeartGold, you catch Kyogre in Embedded Tower. If you transfer either Kyogre or Groudon to the other game, you can catch Rayquayza
at the giant hall in the swirling grass
Yes you can always go back and fight nascour again in realagam tower and get metagross.
In the giant chasm, you can catch them. however, i would recommend catching a metang instead, because metagross are extremely rare.
In Pokemon HeartGold, Metang evolves into Metagross at Lv. 45 .
After beating the Elite Four, head to Steven's house in Mossdeep. In there, take the pokeball. The Pokeball will give you Beldum, which you will have to level up to Metagross.