Thunder Hammer in Heroes 4

Increases the hero's Melee Attack skill by 8, and does 70 hit points of lightning damage plus 7 per level of the hero. Uses both the left and right hand slots.

Long ago, a sorcerer turned myth into reality when he forged the powerful Thunder Hammer. He used it for decades to claim that his power came from the heavens, but when his lies were revealed he was killed and the Thunder Hammer was lost.