I've beat a few gyms and realized that there was a zorua that can be claimed, but I need celebi to get to it. Will anyone want to trade me, I will return your pokemon when I'm done, I have no use for Celebi.
Just so you know, however, it has to be a specific Celebi - the one given out as a special event download in 2011/2010, for any of the fourth-gen games. (See http://www.serebii.net/events/dex/251.shtml for more details.)
Also, the Celebi cannot have already been used to trigger the Zorua event in someone else's Black/White game; it sets a flag on the Pokemon that renders it unable to trigger the event again.