Ascendant Dragon's Wrath Punch Knife

Sap (Mastery): If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.

This weapon is decorated with dragon heads, claws, wings, scales, or Draconic letters. When it steeps in a dragon's hoard, it absorbs the energy of the dragon's breath weapon and deals damage of that type with its special properties. Whenever you roll a 20 on your attack roll with this weapon, each creature of your choice within 5 feet of the target takes 5 damage of the type dealt by the dragon's breath weapon. You gain a +3 bonus to attack and damage rolls made using the weapon. On a hit, the weapon deals an extra 3d6 damage of the type dealt by the dragon's breath weapon. As an action, you can unleash a 60-foot cone of destructive energy from the weapon. Each creature in that area must make a DC 18 Dexterity saving throw, taking 12d6 damage of the type dealt by the dragon's breath weapon on a failed save, or half as much damage on a successful one. Once this action is used, it can't be used again until the next dawn.

Proficiency: simple, punch knife Source: Fizban's Treasury of Dragons p. 25, Ben Huffman - Pugilist (Third Party)