Well, which Legendary Pokemon are you speaking of? It could depend. But the thing I recommend about any Legendary Pokemon-say Uxie, for example-is to use a Timer Ball. It's a somewhat different Ball that becomes pregressively better the more turns there are in a battle. So, therefore, I suggest getting, oh, about 30-40 regular Potions and whenever the Legendary Pokemon hurts you, just by a little bit, use the Potion. It'll count as a turn and, like the Timer Ball's description said, the more turns the better. Also you can switch out your Pokemon over and over again. Maybe, I haven't tried this yet, you could get a Quick Ball and just go, "AIYAH!" and right off the bat try to catch the bugger. Or, (So many possibilities...) you could get a Nest Ball...The weaker the Foe, the better it works basically. So! If you're struggling to get Uxie, as I used 'IT' as an example earlier, Uxie is Psycic Type. Therefore you may get a Psycic Type Pokemon, say Kadabra, get it to Lv. 50 like Uxie (Maybe 49, just to make sure not to murder the Pokemon) and chip off at it's health. You must be patient! If you only get about 1 HP everytime you hit it, DAS IST GOOD! (That is good!) Just keep doing that until if ANYTHING hit it-ANYTHING-then it would fall over, twitch, let it's tongue hang out, and die. After the HP is way way down, you can just heal yourself repeatedly...Or, if every Pokemon is chock-full of health, switch it! And it's good if you fall asleep, too, because then you don't have to worry about accidently attacking it. (I suggest using the buttons on the DS rather than the Stylus, for you might accidently press RUN instead of either BAG or POKEMON) That's about it...I hope I helped out a bit!
Well.. there is Dialga, the cover star of Diamond,who can be found at spear pillar at lv.47,but you need 7 Gym badges first. Then there is Azlef and Uzie,Witch can be found at there lakes.Mesprit Roams Sinnoh.Girintina can be found in turnback cave,but only after you get the national pokedex.Then,of course, there are the event Pokemon
Just play the game and after a while you will find: dialga, azelf, uxie, mesprit, heatran etc. etc. or just trade with friend wich hacked or cloned them
the legendary Pokemon in diamond and pearl are dialga and palkia.
No, a Bidoof cannot evolve into any Legendary Pokémon in Diamond.
Heatran
a lot of legendary Pokemon
Dialga
you cant unfourtanately
arceus
you can't catch it because you already beaten the legendary
no
you can't unless you have AR
Empoleon is not a legendary Pokemon. It is the final evolution of Piplup, one of the starter Pokemon in Pokemon Diamond, Pearl, and Platinum.
That would have to be Dialga.