You must see (Not catch) all 210 pokemon. Manaphy can be seen by looking at the book in the mansion south of hearthrome.
i think it's L+R+SELECT
you need to find 210 Pokemon to complete the pokedex
First complete the sinnoh pokedex, 210 Pokemon
NOTHING
Just go to Pokemon platinum central and click on pokedex and it shows you where to battle all the Pokemon in sinnoh.
you have to beat the Pokemon champion and later on in the game you will complete it
you have to go to Professor Rowan.
There is only one legitimate way to complete the Sinnoh Pokedex. To complete the Sinnoh Pokedex you must trade for the missing Pokemon with Pokemon Diamond, Pearl or Platinum.
this is the code for filled national and sinnoh pokedex enjoy :) 94000130 73877916 72992774 89256734 72973689 67300825 67200937 72028775 d2000000 00000000
complete the sinnoh pokedex and talk to professor rowan.
That pokemon is Azumarill in pokemon platinum in the national pokedex
No. 114 on Pokemon Platinum Pokedex is Tangela.