by event.
you can't. you can catch a shymin in platinum with oaks letter which you can get with an event.
the flower paradise on route 224
It is only found in that form in the new Platinum.
you can't
Shymin is an event Pokemon that can only come when the Pokemon Company wants to give it to the public.
This isn't possible unless you have the Garlecia flower along with the event Shaymin.
shymin
You can get it on a special event,but I'm pretty sure it passed a long time ago. Or, you can just buy an Action Replay and jut get Shaymin.
the strongest Pokemon is arceus.then shymin,dialga,palkia and giratina.
I don't think its there unless you have a cheat code
latias latios darkria shymin etc.
Nothing there is no action replay code to turn Shymin into it's sky form. You just give Shymin an item that makes him transform or go to route 224 I think