Magic Dagger

The Magic Dagger is a Hardmode magic weapon that operates exactly as the Throwing Knife, but uses Mana, instead of consuming stacks of the item. It also causes more than double the damage. A single Magic Dagger can be thrown limitlessly whenever Mana is available, and is never consumed. Magic Daggers also produce a small amount of light. The Magic Dagger is dropped by Mimics.

Trivia

 * The Magic Dagger may be a reference to the many Castlevania games, where a magic dagger can be found and used until the player is out of hearts.