you can't. you can catch a shymin in platinum with oaks letter which you can get with an event.
you can't
Shymin is an event Pokemon that can only come when the Pokemon Company wants to give it to the public.
by event.
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
you cant
shymin
The shymin is only avalible in the wi-fi downloadable mission and the shymin in the mission jumps all over the place so its kind of hard to find it.
the flower paradise on route 224
shymin is because he has seed flare
I don't think its there unless you have a cheat code
latias latios darkria shymin etc.