Umm.. You Might need to migrate from Pokemon emerald
upload from a gba event.
To get jarachi you need to get it from previous Nintendo events or from the action replay.
There are 2 ways. The first and legit way of doing it is to find the bonus disc for the American Pokemon Colosseum and get it that way by trading it to a GBA Pokemon game and transfer it to Diamond and the other way is to use and Action Replay.
Sorry no.
I don't think you can.
No, you cannot breed legendary pokemon...
not thru normal gameplay,but if you have platinum pearl or diamond you can get one feb 27 2010 thru may 12 at gamestop
You can't.
You can get it from an event which you can't anymore, from the Pokemon Collosseum Bonus Disk, or from the Pokemon Channel.
Can't find Jirachi without trade or migrate
You can't Yeah that's 3rd gen...
you need a action replay or a Pokemon event