Nikolas was born out of the relationship between the mender Melkorka and Helvir, the brother of the current Governor of Strand. Helvir however died at a young age and Melkorka kept Nikolas' existence a secret from everyone, hoping to make him the Governor of Strand someday. She also became an advisor to the governor due to her prowess as a mender.
Nikolas grew up to become a handsome man and desired to take the throne of Strand, with his mother assisting him as well. In order to achieve his objective, he set up his own criminal gang called the Aetla Hilmir, which was very secretive and was involved in smuggling. Soon, he approached the Magnus twins, leaders of the slaver gang called the "Vak'auga", who also wanted to take over Strand. He made them an offer of an alliance, promising to smuggle iron ore in exchange for money and their assistance in his efforts.
The Magnus brothers agreed to help Nikolas, but wanted the Aetla Hilmir to first prove they were serious about taking over Strand, by assassinating Ragnar, the son of the governor. Though their attempt failed, the Vak'auga were impressed by their wholehearted dedication and were finally convinced. Nikolas and the Magnus brothers later also allied with the Mársmidr and their varl leader Kjallak, who agreed to offer them his assistance, in exchange for them helping him become the King of Varls.
After Kjallak succeeded in stealing one half of the amulet called the "Gift of Hadrborg", which he needed to convince the varl warlord Vilmundr into believing that he could resurrect the dead varl, from Olaf, he tried to steal the other half from Ulfvalgr about two months before the Third Great War. The attempt however failed, as he did not know he never even had it. Olaf and Ulfvalgr meanwhile made their way together to Strand along with the boy Stefnir, searching for the stolen half of the amulet.
Kjallak's attempted to capture Olaf and Ulfvalgr in Strand, but was foiled by the intervention of Governor's Guardsmen Valgard and Eirik, who was actually the illegitimate son of the governor, and he told Skoegir to inform Nikolas and the Magnus twins about what had happened. Nikolas responded and the Aetla Hilmir were permitted by Kjallak and the Magnus brothers to raid the Great Hall, where Olaf and Ulfvalgr were staying. Infiltrating the Hall as a servant, Nikolas acquired a key to the under hall from Strand's official blacksmith Gylfi, who had secretly joined his gang in the past.
Nikolas later let his men into the Great Hall and led them to the room Olaf, Stefnir and Ulfvalgr were staying in after killing a few people. Eirik however soon learnt about their infiltration and arrived there in time. As he attempted to sneak behind Nikolas, the latter spotted him and fought him, proving to be a skilled opponent. Eirik was however able to fool him and used his axe to smash the burning hearth, sending hot cinders flying in the room and on all of the Aetla Hilmir members. Seeing that there was no way to escape the room, he used a flaming bedsheet to scare Olaf, who destroyed the window wall after crashing into Ulfvalgr and Stefnir, allowing them all to escape from the gang.
Soon afterwards, Eirik learnt from the Vak'auga spymaster Leiknir that the man he had fought earlier was the leader of the Aetla Hilmir, and discovered a varl skull at a Vak'auga warehouse after being directed there by him. He then hatched a plan to lure one of the lieutenants of the triumvirate through a tournament where Olaf and Ulfvalgr will be out in the open. He also had Leiknir inform about it to his master very late, so the Vak'auga and the Mársmidr would struggle to find anyone. Eirik knew that the Aetla Hilmir would attack them, and he told the City Watch of Strand to march there at a scheduled time to prevent it.
Nikolas and his gang went to the tournament disguised as lumberjacks after learning about it, while Melkorka gave false orders to Captain Dylan to delay the arrival of the City Watch. After Eirik and his allies defeated the gangsters led by Ottar in the fight, the Aetla Hilmir soon ambushed them. Eirik and Ulfvalgr however held them off, while their allies escaped with Ottar. Nikolas again fought Eirik, but was wounded by him. He then revealed to him the truth about his parentage, and while the Guardsman was distracted from the surprising revelation, attacked him again. Eirik however soon saw the City Watch arriving and fled, escaping his grasp and giving an opening to Ulfvalgr, before making him drop a pile of logs on the Aetla Hilmir surrounding him. This allowed both of them to flee as the City Watch attacked the gang.
Nikolas' gang was almost decimated by the City Watch, but the triumvirate soon captured Eirik's allies Stefnir and Runa, after they unsuccessfully tried to capture the Magnus brothers. Nikolas wanted to kill them both, but was forbidden by the Mársmidr lieutenant Skoegir, who told him to wait till Kjallak got what he wanted. As he berated Skoegir for ordering him, the Magnus brothers arrived and insulted him for his failures. He attacked the twins as cowards in response, stating how they had only helped in smuggling and bribing, but never took part in any raid. As a fight almost broke out between the three, Kjallak arrived and calmed the tempers.
Skoegir soon found the other half of the Gift of Hadrborg on Stefnir and Kjallak gave the captured Leiknir to Nikolas to be killed, since his betrayal had led to his gang coming close to complete decimation. Nikolas however stated that he must learn to control his anger and keep his alliances, allowing the Magnus brothers to kill Leiknir instead. The twins demanded Runa back after killing Leiknir, since they had given her to him as a slave, but Nikolas reminded them that they needed to deal with Vilmundr first, and left with Kjallak for the temple of Hadrborg in northern Strand where they were going to host him.
Vilmundr arrived at Hadrborg's temple as scheduled, and Melkorka and Kjallak successfully made him believe that they could resurrect the dead varls with the Gift of Hadrborg. The escaped Stefnir however exposed their ruse, while Eirik and his allies attacked the triumvirate at the temple, being guided there by a trail of mead Stefnir had left them. After Eirik and his allies entered the prayer hall Nikolas and the others were in, Nikolas tried going after the Governor's Steward Olvir, but was stopped by Eirik.
Eirik and Nikolas soon engaged in a duel to the death, and the latter berated the former for not taking over the throne for himself instead of letting Ragnar, whom he considered a snob, inherit it. Eirik however criticized Nikolas as a power-hungry madman, and caused his sword to be stuck in his shield while attacking him with his axe. Nikolas desperately tried to get his sword out as Eirik furiously bashed at his shield, but was soon gravely wounded in his forehead as the wood barrier broke apart. Eirik then proceeded to strike at his throat, so he could not threaten Strand ever again.
After seeing her son being mortally wounded, Melkorka attacked Eirik with a fire spell in revenge, but he survived as Olvir and the gangsters he was fighting took the brunt of the blast. She soon fled the temple, but the spell also started a fire in the building, and Eirik and his allies escaped with the wounded Nikolas after taking back the Gift of Hadrborg from Kjallak. Before dying, Nikolas berated Eirik for protecting the governor and Ragnar, stating they were weak, and told him that only nations with strong leaders could survive.
Nikolas' dream to rule was completely shattered, as the rest of his gang was completely destroyed, with the City Watch arresting those who didn't die in the fire or at the hands of Eirik's group. Eirik meanwhile became the new Steward after Olvir's death and two weeks after taking down the triumvirate, decided to give Nikolas a small but honorable funeral out of respect for him belonging to the bloodline of Strand's governor.