Tempest Buckler

The Tempest Buckler has 3 charges. You regain
all charges at dawn, and 1 charge when you score
a critical attack. When you are attacked in melee,
you may spend a charge as reaction. If the attack
would:
-miss: You repel the attacker, dealing 1d12
thunder damage and pushing him 10 ft back.
-hit: You move 5-10 ft back, and the attacker has
to reroll the attack, taking the worse result.
Movement triggered by the Tempest Buckler
provoke no opportunity attacks.