Feather of Ma'at
The Feather of Ma'at is an item used in the Weighing of the Heart ritual. It is weighed against the sins of a person.
In the Yu-Gi-Oh! GX manga, Tragoedia calls Chazz Princeton's "Light and Darkness Dragon" by this name, as the feather was taken in by "Winged Kuriboh" to prevent Tragoedia from reclaiming his heart, and later transferred to the "Light and Darkness Dragon" card by "Winged Kuriboh".