In days of Merakor’s fall, before Merakor dreamed it might end, an Elf Princess fell in love with a Drow named Invri. She offered him safe shelter in her garden while her father hunted him for years. Unable to leave (and not wanting to, for they were both alien to each other), they fell in love and secretly married each other taking his name and pledging herself to the Drow. Her views on magic, the uses of power, and the nature of rulership aligned more with the Drow anyway. She did not like the overt racism she saw manifested only against this one man she had fallen in love with, and so she judged all Drow by Invri, perhaps unwisely for he was atypical of the Drow.
So it was that an atypical Grey Elf forsook the Elves and an atypical Drow forsook the Drow. When the princess became pregnant, Invri knew he had to leave or the child would be executed. If he left, the child might survive even if the charges of forced assault and worse might be laid at his feet. He knew even if his love told him otherwise.
He left and the hunt followed him. The child was taken from the princess, never to be seen in Court again. Invri? He was touched by Heaven in Merakor’s darkest moment. The love that made him different ignited a flame and he vowed to find a different way. He endured multiple assassination attempts until at last, the Drow Nation assembled against him. The gods transformed him into a ghenhalyx, or revenant storm. He awaits his princess and daughter’s return. Until then, he hunts the Drow.
This is one of the many legends of Merakor, yet the ghenhalyx is real. It hunts Drow on the surface of Merakor. They have built stone shelters to outlast the storm’s fury. Any caught outside of natural stone shelters, or without magical protection, are claimed by the storm. Rumors of a haunted banshee-like wail reverberating behind the thunder are told from those who survived with enchanted safeguards. Those slain by the storm cannot be recovered by divine prayers to Lolth. The storm only takes Drow.