Beat the Pokemon League four times and then i think you're supposed to be asked by him and you'll be battling a level 100 torterra , level 100 infernape , level 100 empoleon. I'm not perfectly sure but that's what i think
you get the sinnoh pokedex from professor Rowan afteyou battle the starly with one of the Pokemon in the bag and say yes to the professor and you get the Pokemon and the pokedex.
you have to go to Professor Rowan.
It's a starter Pokemon from Professor Rowan in Sinnoh
Prof rowan is only in diamond and pearl and platinum.
complete the sinnoh pokedex and talk to professor rowan.
you can not get a master ball in Pokemon platinum only the one professor Rowan gives you
You cannot battle Professor Rowan in Pokemon Diamond.
You don't battle your Mom. I think you battle Professor Rowan when you complete the game, well I heard rumors about you Vs. Professor Rowan anyway.
You get Pokeradar from Professor Rowan in his lab after completing the Sinnoh Dex.
Go to lake valor...
Sandgem town is the second town in Pokemon Diamond/ Pearl/ Platinum. It is the home of Professor Rowan
get all the Pokemon in your pokedex from sinnoh then talk to professor rowan and oak will give it to ya