The Nightmare Hex is a Hex that is classified as Dark Magic,It fires a dark waving,spinning jet of dark blue and black flames.It knocks out the target for 2 hours and gives the victim horrible nightmares that seem to be real (althought its not real)
Its unknown who created the Hex,althought it was created somewhere in the 1500.
Andreiko Igorobravitch-Used it as one of his common moves during duels and battles
Yaxley- used it on Gryffindor and Hufflepuff students that he didint like during his Hogwartz years,Alex John for example was his favourite target from Hufflepuff
Pandora Lovegood (mother Of Luna)- Probably was defending herself from a few dark wizards
Xenophilius Kovegood-Was using it on several Death Eaters in order to defend Luna
- The Incantantions to the hex is both on japanese and on latin "Noctis" mean Night "molum comes from malum wich means evil and "yume" (yume is on japanese) means dream or hope or wish