The Akah Ma'at Dimension was a term used exclusively by Oshtur. In today's Magic World, it was more commonly known as the City of Sephiroth. Its inhabitants were the Vishanti's followers—the genuine Bird-Men.
The Bird-Men looked sturdier and more graceful than angels, with a greater variety of hair and wing colors. Though they were not as intelligent as the angelic race and followed a mystical path that left them completely ignorant of technology, they possessed one greatest virtue: loyalty.
These Bird-Men were infinitely loyal to Oshtur, fanatics among fanatics. Even Deathstroke's identity as Sorcerer Supreme carried considerable weight there.
As mentioned before, when the ancient gods left Earth and began dividing up dimensions, Chthon created his own Shining Realm within the Inner Planes, Set opened up the Sea of Snakes, and Oshtur helped Gaea create Avalon. Then that was it.
There were clearly four great ancient gods, so why had Oshtur not made a place for herself in the Inner Planes?
In truth, once she left Earth, she had completely let herself go. After becoming the final victor of the First God War, she gained control over half of Earth, the birthplace of mysticism. Her strength greatly increased, and she immediately felt that the universe was so vast that she wanted to see it for herself.
Her true form was a blue bird, exceptionally skilled at traveling. As the Eastern Star Goddess, her concept also included the trait of "guide," meaning she would never lose her way.
So, after deciding Earth was safe, she bade farewell to her friend Gaea and traveled alone into the distance.
That flight carried her beyond the current multiverse and into a higher plane. She flew and played for countless years, eventually arriving in a certain Single Universe and reaching a region called Cimmeria.
Cimmeria