Darth Nihl, a male Nagi who originated from the planet Nagi, was a warlord on his planet before he became a Sith. Sometime later, Darth Krayt discovered him and offered him a place within his new Sith Order he was rebuilding. Nihl agreed and went through training to become a Sith Lord. He later became a Fist, a title given to those to serve as military commander. In 130 ABY, Nihl was promoted to the position of Hand, Darth Krayt's personal assassin and servant after his predecessor died during the Sith-Imperial War, which the Fel Empire allied themselves with the Sith in order to bring down the Galactic Alliance.
Misson to Ossus
After the Empire captured Coruscant, the capital of the Galactic Alliance, Nihl led the attack on the Jedi Temple as Ossus with orders from Darth Krayt to kill all the Jedi. There, Nihl and his legion of Sith Lords and Stormtroopers, broke through the last lines of defense reaching the space pad with Jedi Master and Leader of the Jedi Council, Kol Skywalker and his former padawan Zabrak, Wolf Sazen defending the ship with the remaining survivors. Nihl engaged Wolf Sazen and cut his arm off and impaling him, mortally wounding him. Right before, Nihl could finish him, Kol kicked Nihl and engaged him in combat. Skywalker's son, Cade soon arrived to help his father in combat, but Kol commanded him to take the wounded Sazen on to the escape shuttle. While Skywalker continued to make his last stand against numerous Sith and Stormtroopers, Nihl managed to come from behind and unleash a powerful Force lightning killing the Jedi master. After the battle, Nihl left the planet, traveling to Coruscant, where he witnessed his master, Darth Krayt ascension as Emperor of the New Sith Empire.
Journey to Vendaxa
Seven years later, Darth Nihl was contacted by Darth Talon, a Twi'lek Sith and Darth Krayt's second Hand, who asked for assistance to help capture Princess Maraisah Fel, daughter of the former Emperor Roan Fel after failing to due to the intervention of Jedi Master Wolf Sazen and Jedi Knight Shado Vao with the help of Cade Skywalker and his companions Jariah Syn and the Zelton, Deliah Blue. Talon commanded Nihl to send Sith Lords to her position to wait for the former emperor to appear and then ambush him and the Jedi to kill them all.
Soon, Imperial fighters arrived to where Cade ship was located, but were quickly shot down by the Sith lords position by Nihl. Talon and Nihl came out of their hiding places to confront Emperor Fel, however Fel revealed himself to be Imperial Knight Antares Draco with his companion Ganner Krieg come to save the princess. As they attacked, Nihl dueled with Sazen again, mocking him saying that he should have stayed dead and hated to kill him a second time. After being saved by Princess Fel who took a blow from a Sith intended for him, and watching his former master being overwhelmed by Nihl, Cade joined Sazen in combat hoping to avenge his father's death. Sazen attempted to stop Skywalker attack on Nihl who believed that Sazen was right about him, and mocked him saying that wielding a lightsaber did not make him a Jedi.Nihl continued to mock him and explained that vengeance was not the Jedi way however, Cade did not care. As the duel went on, Nihl was shot by Syn, however, do to the armor Nihl was wearing, Nihl survived the blast. Nihl then Force pushed Syn away and continued the fight with Skywalker. Nihl tried to land a blow to finish off Cade, but Cade avoided the blow and managed to kick Nihl, allowing him to escape with his friends on the Mynock. Nihl explained to Talon that he would soon be the only Hand once again as he believed Talon would be killed by Krayt for the mission's failure. To Nihl's dismay, Darth Talon was not killed for her failure, but instead, order her to locate Cade Skywalker.
Capturing the son of Skywalker
The search did not take long for Cade Skywalker made his way towards the Sith Temple on Coruscant to save Hosk Trey'lis, a Bothan Jedi Knight that Skywalker turned over to the Sith for a bounty. As he tired to make his escape with Trey'lis, he was ambushed by Darth Talon, whom he bested by tapping into the Dark side of the Force. Before he could finish her off, Nihl appeared and Force choke him from behind knocking him unconscious. Before he could finish him off, Talon informed him that Darth Krayt wanted him alive. Nihl reluctantly agreed and informed his master of Skywalker's capture.
A few days later, Darth Nihl brought Cade to Darth Krayt's chambers as his master asked him to come. When Nihl tried to enter with him, he was stopped by the Chagrian Darth Wyyrlok, Darth Krayt's chief servant. Nihl began to argue with Wyyrlok saying that his place as a Hand was enough. Wyyrlok however, did not allow it. Darth Maladi, the head of Sith intelligence and assassinations, explained to Nihl that the reason why he wasn't able to enter because he was not born a Sith. Krayt only intended for Nihl to be a Fist and only promoted him to Hand because Darth Talon was not ready yet at the time of his predecessor's death. Nihl questioned Maladi to why she wasn't able to enter despite being born a Sith and her response was that she didn't questioned her Master's choice.
As Skywalker contiuned his training under Darth Talon, Darth Krayt became obsessed with him and his potential ability to heal him. This obsession Nihl disagreed with and he confronted Maladi about this issue. She began to wonder herself if Skywalker was capable to of healing Krayt, and what would happened should he die. Nihl firmly believed in the old ways of the Sith that because Darth Krayt had named no heir, it would be a power struggle inside the Sith order. Therefore, Nihl believed that should Krayt failed to be healed, then Skywalker would be named his heir.
Duel with the son of Skywalker
Cade Skywalker had different plans. He never intended to become a Sith and attempted to escape The Sith Temple with Trey'lis once more however, Darth Talon caught him and brought him to Darth Krayt. Nihl watched as Krayt told Cade to kill Trey'lis, so he can finally become a Sith, but Skywalker refused. Krayt in anger, killed him instead leaving nothing but his robe as Trey'lis became one with the force. Cade in rage was ready to kill Krayt, but when he saw a vision of his father, using the Force, Skywalker shattered the transparisteel case his father's lightsaber was in and sent the broken shards towards Darth Krayt, Talon, and Nihl. He then impaled Talon with it taking her out of the fight and engaged Nihl.
Nihl defended himself against Skywalker, while Darth Krayt provoked him in using his anger to kill Nihl in vengeance for killing his father. As the battle raged on, Nihl managed to punch Cade, making Skywalker tap into the dark side of the force and eventually severed Nihl's right arm and knocking him unconscious. As Krayt taunted him to finish Nihl off, Cade refused and attacked Krayt instead. Eventually, Cade was saved by his mother, Morrigan Corde and his friends.
Immediately after Skywalker's escape, Darth Krayt was furious at Nihl for letting Skywalker escape. Krayt intended to have him killed, but Wyyrlok to reconsider, saying that Nihl was still useful. Krayt changed his mind and allowed Nihl to live. Darth Maladi appeared and offered to reattach his arm, however Krayt would not allow it and order her to attach a Yuuzhan Vong bioform replacement. Krayt felt that he was no longer worthy of it. He then replaced Nihl with Darth Stryfe as his Fist and Hand and sent Nihl and Talon to be healed in a Bacta tank. Nihl protested this saying he was worthy of being his Hand, but Krayt refused.
As Nihl continued to heal on Coruscant, Darth Krayt along with Darth Maladi, Stryfe, and Talon traveled to the Outer Rim where on the planet Had Abbadon in response to a female Jedi who claimed to have captured Cade Skywalker. However, the set up was a trap planed by Skywalker and his companions including imperial knights. The Sith lords were defeated, though Darth Krayt barely survived the battle. He was then apparently murdered by Darth Wyyrlok in a barrage of Force lightning. He then took the body back to Korriban in the stasis chamber and made it seem that Krayt was recovering from the battle. After Nihl had recovered fully and attained a new arm, he later joined Wyyrlok to secure the Imperial throne in the name of Darth Krayt.
Attempting to discover the truth
While Darth Krayt had managed to deceive most Sith Lords such as Darth Stryfe and the high Moffs into believing Emperor Krayt had survived the assassination attempt on his life and had gone into a long term stasis to heal his wounds, Darth Maladi had her doubts. Nihl met with her on the planet Wayland where she discussed her concerns that Darth Wyyrlok would attempt to seize power and would eliminate those who he considered a threat. Maladi believed that because she and Nihl was not born Sith, they would be killed. She then told Nihl that she considered him a far more suitable candidate to lead the Sith Empire and convinced him to travel to Korriban to confirm her suspicions that Darth Krayt was dead. Nihl made his way to the chamber of Darth Krayt where he was met by Darth Talon who was guarding the entrance to the stasis chamber. When she refused to let him enter, Nihl deceived her saying that Darth Krayt summoned him. When they entered the room together, both Nihl and Talon was surprised to discover that Darth Krayt's body was missing and all that was left was his armor.
Soon afterward, Lord Nihl contacted Darth Wyyrlok informing him that Krayt's body had disappeared. When Wyyrlok arrived, Nihl listened as Wyyrlok claimed that someone in the Order must have murdered him and taken the body. Wyyrlok then told Nihl to keep this matter quiet while Wyyrlok ruled the Sith until a replacement could be chosen. He then appointed Nihl as his advisor. As his first suggestion, Nihl stated that Darth Talon may have been responsible for his death, as she was the one who was watching the chamber at the time and had mysteriously disappeared. Wyyrlok agreed and told Nihl to find and questioned Talon while he returned to Coruscant to tend to the Empire. Later Nihl pursued Talon into the Valley of the Dark Lords. While sensing Talon was here, little did he know, Darth Krayt was alive and well.
Later, Darth Nihl finally caught up with Darth Talon and started a duel with her, but was interrupted by Darth Krayt. Krayt revealed to him that he was building an army of obedient Sith troopers and new star fighters.