you need a event.
no you don't
No.
Hack of trade.
You can get the Celbi in Pokemon Nirvana by having Pikachu on the correct level and then you climb up the Cyrus tree. You will then see the Celbi in the tree.
celbi cannot be cached on Pokemon heart gold and soul silver to get celbi in gold and silver you haft to cheat sorry:( not god at English
an event from new york.
No
yes he has dig
you can get that Pokemon by obtaining all the Pokemon in the hoenn region.
Action replay
At sky pillar.
It's only an event pokemon. Check out Serebii.net for details on that