After you've placed the order, we assign a PRO player with Legionnaire Murky item in his inventory. He works according to the agreed schedule and will contact you in-game to trade you Legionnaire Murky.
As soon as you receive Legionnaire Murky you can learn it from your inventory, and it will become available to all the characters on your account. If Legionnaire Murky is the Blizzcon promotion code, you will receive a digital code to redeem at your battle.net account page.