Black Númenóreans are a fallen race of Númenóreans (a group of Men that lived in the north-western part of Middle-earth, which became one of the most advanced mortal cultures) that are loyal to the Númenórean crown and oppose the Valar and the Elves. They have been corrupted by the influence of Morgoth and Sauron and serve them.
Though they are a "fallen" race, they are still Numenoreans and are able to live for hundreds of years and can survive lesser injuries such as when Talion stabs the Tower four times and the Tower seemingly survives until stabbed a fifth time by Talion. Though they are corrupted by Morgoth some of the Black Númenóreans were able to snap out of the power that held them and became good again.
Black Númenóreans • Uruk