Magpie, Blade Of Rebellion

When Magpie, Blade Of Rebellion enters the
battlefield, you may destroy target creature with
mana value 2 or less. If it wasn't cast, you may
instead destroy target creature with mana value
4 or less.
Whenever a creature dies, you may pay {b} and
discard a card. If you do, put Magpie, Blade Of
Rebellion on the bottom of its owner's library.
Rebels need noble ideals and bloody hands.