Presage

Concept: “As you put on the cape, feathers start growing from under your skin...”
Content: A cape to become the bird of your dreams (or at least omens).
Writing: A surprisingly flexible and self-regulating magic item with gut-wrenching descriptive text.
Art/design: Some winged angel, tastefully protected by some boxed text.
Usability: Make sure to emphasize the bone-crunching transformation.