Murasama, Sam's sword

Equipped creature gets +3/+1, First strike and
"Whenever this creature gets blocked, the
defending creature takes 3 extra damage."
{3} Equip creature.
{2} Unequip creature.
I said my sword was a tool of justice, not used
in anger, not used for vengeance...But now...
Now I'm not so sure and besides, this isn't my
sword.