After you get the National Dex, go to route 214 and you'll find Spring path that lead you to Sendoff spring, use Rock Climb 2 times and you'll see the entrance to Turnback Cave, Girantina is in it, save before you procede.
You have to transfer caterpie from a GBA game with pal park.
Yes put leafgreen in the GBA slot in your DS and put Diamond in the DS Slot play Diamond and choose migrate to leafgreen follow the instructions then choose six Pokemon to migrate after your done go to the pal park to capture the 6 Pokemon you chose.
dragon claw, ominous wind,and shadow force that's what the ones i know but to be honest hes not that strong your starter Pokemon you picked if its at least lvl 60 is better In Pokemon Diamond giratina moves are shadow force,slash,heal block and Earth power.(hes a level 70)
Through normal gameplay you can't but I'll tell you some ways to get a legitimate Lugia.In third generation,if you have the Mystic Ticket,(which you can't get anymore,except through cheating) you can capture it at Naval Rock,then you can migrate it to Pokemon Diamond through the Pal Park.You can also get one by trading with Pokemon XD Gale of Darkness.Purify Shadow Lugia by getting all of the "chambers" in the purification chamber to be a "best circle",then trade it to a third generation game,and migrate it to Pokemon Diamond.Lastly,you can capture one in Pokemon SoulSilver,through normal gameplay,or Pokemon HeartGold in the post-game storyline and trade it over to Pokemon Diamond. These are the real ways to get a Lugia in Pokemon Diamond.
Catch a Banette of any gender and breed it with a Ditto. Shuppet eggs take about 6,400 steps to hatch.
After you beat/catch garintina in diamond you could keep training or just keep fighting the pokemon league. Also, you could go catch more legandary pokemons.
garintina
You have to beat the guy who wants to to use Pokemon for no good.... then you can get the Pokemon..... if you beat it then you'll have to wait until you beat the champion.
You Can't
To get a Giratina in Pokemon Diamond, you'll have to catch it in Pokemon Platinum, then trade it to Diamond. However, when you catch it in its Origin Forme and trade it to D/P, it'll revert back to its original form, due to Pokemon DP not having the Giratina Origin Forme sprite programmed into the game.
capture the legendary and train your Pokemon
To catch garintina
You actually cant physically catch a rayquazza in diamond or pearl. If you have diamond or pearl and you want a rayquazza you need to get pokemon emerald capture it on there and then migrate it onto your peral or diamond game. Cheers boiz and gyrls.
It's on route 228.
in snowpoint cave somwhere
capture one in the safari zone
Trade it with ur friend.simple.