RE: The B/W Questions and Answers Thread
^no, if you knock out Zekrom at N's Castle, the game with rewind itself to start the battle over as if it never happend; if you lose the same thing occurs, and you can not SR for a shiny at the Castle unless it goes to the DragonSpiral Tower; also, once you do one battle with it, the Zekrom will be the same every time (I tested it with a ROM)