A beautiful magical viol bow made from pure ruby, with bow strings made from a fine crystal, ever glowing with a magical light. Arco draws from Bardic Inspiration energy and transforms it into more powerful forms. It can use the following features:
Piercing Melody. As an interaction, you can speak "Arco" to transform it into a weapon, or back into a viol bow. It can assume the form of a +2 rapier or a +2 shortbow.
Soothing Melody. You can expend 1 use of your Bardic Inspiration to heal a creature you can see within 30 feet for your bardic inspiration die + your Charisma modifier. Alternatively, you can spend 2 uses of your bardic inspiration to heal each creature within 5 feet for the same amount.
Thunderous Melody. You can expend 1 use of your Bardic Inspiration to imbue your next weapon attack with concussive energy. Your next melee weapon attack deals bonus thunder damage equal to 2x your bardic inspiration die, and the creature must succeed on a Constitution Saving Throw or be knocked prone.
Heroic Melody. You can expend 3 uses of your Bardic Inspiration to grant Temporary Hit Points equal to your Bardic Inspiration die plus your Charisma modifier to each creature within 30 feet. For the next minute, creatures within 10 ft. gain a bonus to attack rolls and saving throws equal to your Bardic Inspiration die (requires Concentration).
Proficiency with a Rapier allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Vex. If you hit a creature with this weapon and deal damage to the creature, you have Advantage on your next attack roll against that creature before the end of your next turn.
Notes: Bonus: Magic, Damage: Thunder, by a bard, Finesse, Vex