Wave

Held in the dungeon of White Plume Mountain, Wave is engraved with images of waves, shells, and sea creatures.

You gain a +3 bonus to attack rolls and damage rolls made with this magic weapon. When you roll a 20 on the d20 for an attack roll with this weapon, the target takes an extra 21 Necrotic damage.

While holding Wave, you gain the following benefits:

Combat Ready: You have Advantage on Initiative rolls.

Underwater Adaptation: A bubble of air forms around your head while you are underwater, allowing you to breathe normally in that environment.

Aquatic Command: Wave has 3 charges and regains 1d3 expended charges daily at dawn. While you carry it, you can expend 1 charge to cast Dominate Beast (save DC 20) from it on a Beast that has a Swim Speed.

Globe of Invulnerability: While holding Wave, you can cast the level 9 version of Globe of Invulnerability from it. Once used, this property can't be used again until the next dawn.

Sentience: Wave is a sentient weapon of Neutral alignment, with an Intelligence of 14, a Wisdom of 10, and a Charisma of 18. It has hearing and Darkvision out to 120 feet.

The weapon communicates telepathically with its wielder and speaks Aquan.

Personality: Wave zealously encourages mortals to worship sea gods and has a habit of humming sea chanteys. Conflict arises if the wielder fails to further the weapon's objectives in the world.

Destroying Wave: Wave can be destroyed only on the island of Thunderforge, where it was forged. The weapon must be melted down by a storm giant or someone imbued with a storm giant's strength. Destroying Wave angers a god of the sea, who sends powerful agents to attack the island and punish the destroyers.

Topple (Mastery): If you hit a creature with this weapon, you can force the creature to make a Constitution saving throw (DC 8 plus the ability modifier used to make the attack roll and your Proficiency Bonus). On a failed save, the creature has the Prone condition.

Thrown: If a weapon has the Thrown property, you can throw the weapon to make a ranged attack, and you can draw that weapon as part of the attack. If the weapon is a Melee weapon, use the same ability modifier for the attack and damage rolls that you use for a melee attack with that weapon.

Versatile: A Versatile weapon can be used with one or two hands. A damage value in parentheses appears with the property. The weapon deals that damage when used with two hands to make a melee attack.