Put all creatures on the bottom of their owners' libraries.
8/1/2008 All creatures leave the battlefield simultaneously. They’re not destroyed; they’re just put on the bottom of their owners’ libraries. This includes token creatures, though they’ll cease to exist as soon as Hallowed Burial finishes resolving.
8/1/2008 Each player chooses the relative order of the cards they are putting on the bottom of their library, regardless of who controlled them while they were on the battlefield. Players don’t reveal this order to other players.