you need to hatch a togepi in soulsilver or heartgold then trade it to pokemon diamond
You get a togepi egg in Pokemon Platinum, not Diamond.
togetic-togekiss
it evolves certain pokemon, like togetic
Togetic won't evolve in firered only in diamond, pearl and platinum.
Roselia to Roserade and Togetic to Togekiss
No it is not possible but you can evolve it on Pokemon Diamond and Pearl if you wanted.
It evolves into Togetic and then in later versions of Pokemon like Diamond/White it turns into Togekiss.
the shiny stone is used to evolve Togetic and Roselia.
Togetic cannot be found on Diamond and Pearl, check the question "How to get Togetic?" for more details on how to get it.
no 1 cause togetic is gd
sorry no trainers have a togetic in Pokemon soul silver but you can get a togetic when you get a togepi evolve it by happiest and it will evolve to a togetic.
you battle togetic at the Pokemon league