This is quite simple to do all Pokemon (except for legendarys and Saphire esclusives) can be caught and trained up to evolve you just need patience and Saphire aswell :-)
Oh and don't ignore all cheats saying catch Deoxys or Jirachi cos i have completed the hoen dex without cheats.
So if you need help message me on YouTube :-) and I'll tell u how to catch that Pokemon :-)
My you tube is Barstretch
I'm not sure what you mean by the question. If you mean "How do you complete the Pokedex in Pokemon Platinum", then that's simply by finding the Pokemon. You don't have to catch the Pokemon. All you do is have to see them and as soon as you've seen all the Pokemon in the Pokedex, that's considered to mean you completed it.
This is why I recommend you battle trainers instead of avoiding them. By battling the trainers, you'll get to fill your Pokedex a lot faster than just trying to encounter the Pokemon.
http://www.serebii.net/platinum/nationaldex.shtml
That website will tell you where you can meet each Pokemon.
all the ghost pokemon are on route 121 for duskull and route123 but shupettte and duskull can be found at mt. pyre and at sky piller you can find dusklops the evolved form of duskull. also if you evolve shupette to banette thats a nother but im not done elite foyr phonebe has a sableeye, and thats all from memorie folks hope i helped.
In order to obtain the national pokedex, you must beat the pokemon league and see the first 200 pokemon in the Hoenn Pokedex.
well you need to have all your Pokemon in your pokedex and when you get your national pokedex you will get breed
press switch pokedex on the national pokedex and you will be using the sinnoh pokedex
in the sinnoh pokedex dusclops, in national pokedex aipom
You have to have national pokedex.
Medicham, the evolution of Meditite X24
420
there are a total of 202 pokemon
Raichu
Yes, if you trade it you will automatically get the national pokedex on Pokemon Emerald
In the both the Hoenn and national pokedex, Pokemon number 367 is Huntail.
weedle
All 386 pokemon from Bulbasaur to Deoxys
you must talk to professor birch after beating the Pokemon league
hoen region and when you beat the elite for the national pokedex
Beat the Elite Four and get the National Pokedex
Just catch the most Pokemon you can ;)
You go to route 224 after upgrading your pokedex to the national pokedex and have Pokemon emerald verison in the GBA slot #2.