Wondrous Item, common (requires attunement by a by a player character or non-player character.)
This shimmering Amethyst-colored robe denotes a member of the knightly Order of the Amethyst Robe, and is emblazoned with the receiving knight's insignia.
Once per day while attuned to the Amethyst Robe, you can cast Thaumaturgy as an action, using Charisma as your Spellcasting Modifier. When you do so, you can choose to make the cloak billow dramatically, as with the Cloak of Billowing.
Notes: by a player character or non-player character.