Stoneforged Animist Sword

When drawn the sword whispers, "Swift defeat to
my enemies." When you attack, you can, as a
Command phrase, say, "For all of Zendikar". The target of your Attack becomes your Sworn Enemy
until it dies or until dawn seven days later. You
gain an additional +1 to hit. On a hit, your Sworn
Enemy takes an extra 1d6 damage.
While your Sworn Enemy lives, you have disadvantage on Attack rolls with all other
Weapons.When your Sworn Enemy dies, you can choose a new one after the next dawn.