House of Arkon

"Ya see that eclipse iconography? Yea, shit's everywhere"
-Luca 'Carrion' De Rosa
The House of Arkon is a mythical demon house which was said to have lead the Seven Empires of Darkness during Ragnarok, and is said to have been slowly extinguished in the following Tenebrous Era of Arkon by Axios the Divine. House Arkon is the namesake of the world of Arkon, originating from the fact that at its height, it ruled nearly 80% of its total landmass. After the end of the Arkon, the demons would go without a ruling clan for over a thousand years, until the first house I could archeologically verify, the House of Tonaltzintli, took power in the First Era. 
During its reign, the Arkon were said to worship and pull power from Angra the Betrayer, lord of evil and darkness, and head of the Venerate. The Arkon's founder, Atraxas Arkon, was said to be his wife, a rabid monster he found while travelling the wilderness of Old Kondrakis. The myth tells the story of how, when Angra saw a demon- which were back then only rabid monsters- tear apart a giant spider in defense of its cubs, and decided to elevate her to being a fully intelligent and sapient being. In exchange, she swore she and her family would serve him forever. 
Today, many archeologists and scientists question the validity of the Arkon, as practically none of their culture remains. It is generally accepted by the mages of Arkon, and mostly accepted by the mages of Terra, that the first demon house was the Tonaltzintli, and that the Arkon are a myth created by the House of Aundali to claim legitimacy for being the Royal House during the 7th Era.