Nacht Faust is a former nobleman of House Faust, the vice-captain of the Clover Kingdom's Black Bull squad of the Magic Knights, and a devil host. He spends several years working as a spy within the Spade Kingdom. Nacht uses this magic attribute to manipulate shadows. He is able to slip in and out of the shadows of other people and things, immobilize people who step into shadows, and physically restrain people with shadows. Nacht combines his Shadow Magic with Yami Sukehiro's Dark Magic. The two magic attributes continuously synergize and strengthen each other. Nacht possesses tremendous levels of physical endurance, as shown when he continues to fight two highest-ranking devils after being pierced with multiple needles of burning ice.
As a nobleman and the vice-captain of the Black Bull squad, Nacht possesses a large amount of magic power. He can increase his magic power by using his devils' power. Nacht is host to four mid-ranking devils who grant him power: Gimodelo, Slotos, Plumede, and Walgner. He uses four relics linked to the devils to temporarily summon them into the living world, either as large masked beasts or as small familiars. He can also merge with their larger forms, allowing him to access the power of Unite. As he has four devils to perform Unite with, he has at least four different Unite Modes, with each mode giving his magic an additional effect or ability to use in battle. Nacht can control all the mana in an area around him to increase his spells' power and range. Nacht possesses a grimoire that contains various shadow-based magic spells. Nacht carries four relics that are connected to his four devils: a feather, two claws or fangs, and a braid of hair. Nacht is a pragmatic and logical person. He knows that Asta has no chance of saving Yami from the Dark Triad alone. He believes that losing a fight is the loser's own fault and considers losers to be idiots. Nacht is not shy about expressing whether or not he likes someone. He is also unafraid of expressing his dislike of all the Magic Knight captains to their faces. He has a very specific ideology about what determines good and bad; something is only good if it is good from the start, where as something bad that becomes good, though a pleasant surprise, is still ultimately bad. Nacht believes that doing good does not make up for past wrongs. This belief likely stems from his inability to forgive himself for his actions.