Willowwind

Rapier, legendary (requires attunement by a Druid)

You gain a +2 bonus to attack and damage rolls with this magic weapon. While you hold it, your spell save DC increases by 2, and you become proficient with Rapiers if you are not already.

While holding this weapon, you are under the effect of the Barkskin spell.

You can cast the following spells using your spell save DC and Spellcasting ability: Animal friendship, Call Lightning, Freedom of Movement, Sunbeam, and Polymorph. Each spell can be cast once a day, and cannot be used until the next dawn.

Guardian of the Forest. Whenever you are shapechanged, this weapon immediately begins to hover at your side. It flies up to 30 feet, and attacks one creature of your choice within 5 feet of it. On your subsequent turns, you can use your bonus action to move it up to 30 feet and make one melee weapon attack. The weapon uses your Dexterity or Strength score of your normal form for its attack and damage rolls. When you resume your normal form, this weapon automatically returns to your hand.