In Pokemon Coloseum I have completed the Shadow Pokemon lab but I killed the Shadow Raikou is there anyway of battling it again? Thanks in Advance :)
Yes. You'll have another chance to battle him in Reglam tower later in the game. There's also a room in the game where you can rematch missing Pokemon.
Might I add, if you go to the deep collesseum hell rebattle you unlimited times as a boss to try to catch him.