Shadow-Walkers

TThe Shadow-Walkers are the very elite of Alith Anar the Shadow Warriors, with each of their number having to be in the Shadow King's service for hundreds of years.

Overview
Bands of Shadow Warriors are often led by the most capable of their kin, known as Shadow-Walkers. To reach the rank of Shadow-Walker an Elf must have hundreds of years in the field under his cape and have proven to be utterly dedicated to Nagarythe’s cause. Compared to other High Elves, they are merciless, cold and callous - almost indistinguishable from the Druchii they hunt. They are unquestioningly loyal to their king, and as such, will form Alith Anar’s elite retinue on occasions when he is forced into open battle.

Source

 * : Total War: Warhammer II