Once upon a time, there was a large powerful kingdom. It was in a huge drought and everyone was really thirsty. So the king decided that he had to sacrifice his daughter to the god of weather, Zephyrus in order for it to rain. But at the last minute, he saves her to make her his wife and makes it rain.
Zephyrus brought her to his palace in the sky and told her she can do whatever she wants except for one thing. She could never go into the west tower of the palace.
That was a test and you failed it. I'm sending you back to your Kingdom
Also, I curse your kingdom to never have rain.
Adelpha obeyed but after a month she got bored. One day, when Zephyrus was out running errands, an old woman came to the palace in the sky and told her to go into the tower and she would get to go home. Adelpha did this as she missed her family and wanted to go home.
She went into the west tower and there, she found a monster she realized that it was all a test from Zephyrus. She wished she had listened to his rule. She tried to run away but she got injured by the monster.
It she almost died but she was saved by an angry Zephyrus. He is really angry that she didn’t listen to his rule and failed the test so he sends her back to her kingdom and curses it to never have rain.
Eventually, the kingdom dried out and everyone left, leaving the king and Adelpha to die of thirst and the kingdom became a vast desert. That is how deserts were formed.