The best would be the "Battle Factory" with 5 Bp
A Riolu, which can evolve into a Lucario.
beat the first gym leader in oureburg city he then gives it to you
As u enter the battle frontier a lady stops you a does a lots of conversation and at last gives you the point card . It measures your battle points and can help you in buying items from battle points exchange center in battle frontier. It is located at the entrance of the battle frontier.
dont cheat it ruins the game
Riley on Iron island gives it to you, otherwise you can breed Lucario and ditto in the daycare and get it.
Cynthia gives it to you.
jortan
Cynthia's grandmother gives it to you.
someone gives it to you.
you can not get a master ball in Pokemon platinum only the one professor Rowan gives you
cyrus gives it to you
The Champion probably
Im sorry, but there is no happiny egg in Pokemon platinum. You got diamond or pearl? trade from there
A fisherman at the fight area gives it to you.
Cyrus gives u one
They altered and changed a bit here and there in Platinum, and the hiker no longer gives you Happiny in Hearthome City.
no man gives you a happiny platinum only in diamond and Pearl