this piece can be used as a decorative Queen in normal, or "Queen's" chess, as well as is a "Revealer" in the ancient and exotic game of Complete Timur Chess, or Perfect Tamerlane Chess.
"During the reign of Timur Lenk, also called Tamerlane (1336 - 1405), this game was played often in Persia. Some old sources tell that Timur invented the game himself, but this attribution is, as more of such attributions, not necessarily true. The game is a large variant of Shatranj, the orthodox chess-game of that period. As a consequence, the game was also called Shatranj Kamil (perfect chess) or Shatranj Al-Kabir (large chess).
The game was mentioned in Murray's History of Chess, and discussed in more detail, with sample game, in the book of Gollon." - http://www.chessvariants.org/historic.dir/tamerlane.html