Nitehorn

The language of Demons, Devils, and The Hells, the letters and writing of this language are exactly upside down of the letters used for @holi. It is believed that the two languages were created at the same time the two groups were created, designed to engrain the natural fear and hatred they have for one another.
Nitehorn is included in the Gether Guide to Languages on DrivethruRPG:
https://www.drivethrurpg.com/product/328473/Gether-Guide-To-Languages