The Fist of Ra-Den is a 4 Mana Cost Legendary Shaman Weapon card from the Galakrond's Awakening set!
After you cast a spell, summon a Legendary minion of that Cost. Lose 1 Durability.
Flavor TextThe mighty Ra-den was known as the Keeper of Storms. Unfortunately, he could not keep his fist.
The Fist of Ra-Den Additional Information
If there are no Legendary minions at a given mana cost (e.g. 0 mana), the card will not summon anything and won’t lose Durability. (Source)