The Scarlet Queen, also known as the Scarlet Phoenix, is one of the Ministers of Creation, the ruler of the Yang World (though the history of the Hsien names the phoenixes as the masters of Yin). Her mate is the Ebon Dragon. Together they created the Wan Xian — the Ten Thousand Heroes — to protect the world in the name of the August Personage of Jade, and birthed numerous shen.
In the modern era, the Scarlet Queen and Ebon Dragon are — according to Lucifer — the last remaining Angels on Earth. They are probably the "Messengers" responsible for creating the imbued, or at least the leaders of the factions championing the virtues of Zeal and Mercy. As the Scarlet Queen represents Yang, the active principle, she would represent Zeal. The best of both principles were used to create the Vision creeds.
Based on the lore of the Fallen, the Scarlet Queen is also identified as Ziana, the Seraph of the Cycle, ruler of the Sixth House of angels. As with the majority of angels, Ziana remained loyal to God, while those of her House who rebelled became the Devourers. Ziana is said to have become the World Tree, which may mean that she became Gaia. This agrees with the Fallen's belief that the Garou and Fera, both intimately connected with Gaia and the Yang World, are descended from the Malhim, one of whom praised Ziana with his last breath during the war. The Beast Courts of the Middle Kingdom, however, identify Gaia as the Emerald Mother, a different being altogether with roughly equal status to the August Personage (though many spirits allied with her do dwell in the Yang Realms). It is of course understandable that the Hengeyokai, having been created by Gaia, would view her in the most positive light.
"Green mother Nature, Red of tooth and claw."