There was once a deck that played Puresteel Paladin and another similar card (to be seen later on this list) and a bunch of zero-mana equipments like [c]Paradise Mantle[/c] and [c]Kite Shield[/c]
But once a split second spell is played, nothing can be played
(A good test is if you would recognize the card if it were played across the table in a match against you.) This alter is probably a lot of fun for Commander or casual play, but its not something you can play in a tournament.
The number of cards you put on the bottom equals the number of times you've mulliganed
Containment Priest completely shuts down Dredge, Oops and Reanimator strategies (when you come across them) and, frankly, has caused more immediate concessions than almost any other sideboard card
The bottom of the package features a paper zip pull to open it, and the inside reveals a recyclable deck box and packing tray: There's no longer a plastic tray holding an oversized shoebox-style deck box