Yuuka had managed to do it again, everyone but those with no fears revolved around her. Most of them people who sought for power. She wasn't a sociopath, she could feel empathy for people, but only to few, for her humans only mattered to her in a crowd. To animals humans are sociopaths, to humans youkai are too. When an animal shows traits of a human they will relate to it and feel sorry for its pain, they will even give them rights. Yuuka was only empathic with very powerful humans for the same reasons.
She was particularly fond of the Hakurei bloodline, and treated them as equals. Marisa was someone who earned her respect, a common human who slowly became strong enough to be considered youkai. Not a saint, she was a human who slowly was turning into a youkai. It wasn't the first time a human turned into a youkai, Byakuren, Lilith all of them common humans whose tenacity turned them into something of the likes of gods. Sakuya, she didn't admit it, but she felt a lot of respect for her too. Now Accelerator had managed to become one of those few humans Yuuka didn't treat like animals.
It was actually Amaterasu the one who set her to take care of humanity, it was a bet she lost to the Queen of gods. If Amaterasu managed to turn a human into something worth saving Yuuka would agree to protect humans from extinction. Yuuka never thought those small pieces of dust could attain such levels, but then the Hakurei bloodline was created. They were only female born, Yuuka agreed to make them by using a small piece of her soul. So the bet was actually fair.
They were not very religious even though they were made priestesses. They believed in god since they had many proofs for its existence but because they had came from Yuuka they didn't like to follow any god, mainly because they were in a very small potions gods on their own. Practically powerless, but they learned quick. A Hakurei maiden would become quite strong at adulthood, not because of their soul since it held nearly the same power of a human's, but because their own means.
Their moral code was extremely close to that of Yuuka. Amaterasu was smart, she knew the only way Yuuka would get a good first impression from humans was if they were made after her own image. That is how the seraph who treats humans as animals became one of its guardians.
She had taught some of them, and enjoyed their company. She was so fond on them she turned her shape into that of a human to be able to interact better. She didn't want to be worshiped anymore, when she was shapeless the shrine maidens treated her with great respect and fear. When the Hakurei god took a human shape they started to talk like friends. Eventually the Hakurei bloodline forgot the fact that the green haired was their god.
Yuuka rarely appeared in human form, mostly she did it through the dreams of the shrine maidens. Humans had imagined her with many shapes but she never kept one for too long. Amaterasu had tried to turn her into a god many times, Aranjani, Durga, Xipe, Gaia, but she stayed as a gremlin. However in the later years she started to realize how youkai started to crowd around the Hakurei shrine.
Another gremlin proposed an idea to Yuuka, for them both to leave the comfort of their ethereal existence and create a paradise for those beings who were not liked by most gods, a refuge. Yuuka agreed to it with the condition that they both made this pardise a unified world. Those hells which were not in Yama's jurisdiction, worlds of demons who liked to live alone. Yama found out about the plan, but she liked it too, she would grant them permission so no god or gremlin would bother them in this demon world, with a few conditions.
Yama was to be the judge of death in that world, they would be judged on their own moral code to be fair. She also wanted to place a small heaven in there, so those who followed the outside codes would go to a fair place too. Hakugyoukurou was to become a part of their land, she had appointed a human ghost in the care of it, and she created the Konpaku bloodline to keep this small heaven protected in a world of demons.
Yuuka finally made a permanent human shape for herself. She had no name at the time so she named herself Yuuka (a nickname a shrine maiden had picked for her because she always smelled like herbs) her surname was Kazami in reference to her family line, wind watcher, Rudra was the name of those deities of destruction, Rudra was also referred as a deity of wind. A riddle anyone solved but a nun she met later on.
She made a world for herself in the middle of the dream world, a place she liked to visit and Gensokyo the new land she and her friend had created. The gremlin who had the idea already had a name for herself, she even held a human shape from a long time ago; Yakumo Yukari. They made this land around the shrine of the human bloodline Amaterasu made for Yuuka, that girl was to be set as the guardian of that land. Yukari also found the girl quite sympathizing, their personalities were made specially for youkai to like.
Yukari on her own was a gremling worth mentioning, she was never taken as a god by any human but one crazy writer who ended up calling her "Yog Sothoth". She found the name amusing but she liked her current name too much to change it.
Slowly Gensokyo became a target for many, humans didn't like to go there while the gods considered offensive that Yuuka and Yukari had left them to make such a mockery of them. Keeping all of their enemies safe, it was an insult. Yukari decided to seal the place, while Yama created a whole new universe for it to sit on. Some people think it was Yuuka the one who did it, but her creation abilities were never that good.
The world didn't have a name at the time, Yuuka named it Land of Fantasy, or as we know it Gensokyo. Yukari made sure it stayed hidden, to protect it, Yuuka destroyed anything that harmed the land, while Yama made sure people behaved. Without knowing they three had taken the role of the trimutri of that new universe.
The Hakurei shrine maidens acted the same way Yuuka would if she was in their place, because they were part of her. There were always two Hakurei souls, one for the child the other for the mother, when one died the soul would go to the ying yang orb, when they were born the soul would go out of it and get into the child. It was a gift Amaterasu gave the Hakurei to fill many gaps, it made sure their bloodline carried part Yuuka's soul and in the beginning it was to protect themselves in case Yuuka didn't like them.