You had to get the event that was going when the game came out, there's also another one going, but it ends the first of 2012. If you mean like you see a trainer have it, no, no trainer owns a Victini.
you don't see pokemon
You have to trade one from Pokemon White.
You can't get Tornadus on Pokemon White. Tornadus only appears in Pokemon Black and the only to get it is to trade it from Pokemon Black.
idk but if you look up on youtube it says catching arceas in Pokemon white/black im really not sure but i think its yes? remember go on youtube to see if its in Pokemon white/black PS: i have Pokemon white.
when you have the nat dex, you can see every pokemon in the universe except from the ones in black and white. so the ones from black and white are the only ones you cant see
celebi.
I'm sorry but you cant get a mew in Pokemon black or white you can only get them when distributions are out check every now and again and see
You can watch Pokemon episodes on Pokemon.com.
Yes, it is found in White Forest when Grace is the resident. If not, then use the Entralink to go to Black City from Pokemon Black to see that resident.
Pokemon will be released when you go to Australia and see when it will be released
For a list of all known Pokemon, see the related link.
No, you dont see him again.