Ruidium Yklwa

This magic weapon has a dull, rusty color or has veins of ruidium running through it. While this weapon is on your person, you gain the following benefits:

• You can breathe water.
• You gain a swimming speed equal to your walking speed.

Ruidium Strike: A creature you hit with this weapon takes an extra 2d6 psychic damage.

Ruidium Corruption: When you roll a 1 on an attack roll made with this weapon, you must make a DC 20 Charisma saving throw. On a failed save, you gain 1 level of exhaustion. If you are not already suffering from ruidium corruption, you become corrupted when you fail this save.

If Ruidium Is Destroyed: If the Apotheon is killed or redeemed, all the ruidium in Exandria is destroyed instantly, and a ruidium weapon becomes a +2 weapon.

Thrown: If a weapon has the Thrown property, you can throw the weapon to make a ranged attack. If the weapon is a melee weapon, you use the same ability modifier for that attack roll and damage roll that you would use for a melee attack with the weapon. For example, if you throw a handaxe, you use your Strength, but if you throw a dagger, you can use either your Strength or your Dexterity, since the dagger has the Finesse property.

Proficiency: simple, yklwa Source: Critical Role: Call of the Netherdeep p. 216