Nadir is the rune word 'NefTir' for helms in Diablo II: Lord of Destruction. Nadir's most prominent feature is its Cloak of Shadow charges, which allow the character to disable ranged attacks for a period of time, which can be occasionally handy. The charges are expensive to repair, but because the runes are so easy to get, it's a viable option to simply make a new one for more charges. It's not a good rune word for general purpose fighting, though, due to lack of other useful mods, as well as some negative traits.