Thundering Hammer

Weapon gains a +1 bonus to attack and damage
and deals 1d6 extra thunder damage, releases a
loud thundering crack. As an action, the weapon
can be slammed into the ground, each creature
within 10 feet must succeed on a DC 15
consitution saving throw or take 2d8 thunder
damage and be knocked prone. Successful save,
receive half damage and not prone. Creates a
thunderous boom, audible out to 300 feet. Can't
be used again in this manner until after long rest.