''"I am the Young Red Viper of Dorne; those who hear me, I offer you a chance to lay down your steel, or feel the wrath of Dorne from my bare hands !!!" Niall in the tunnels under the Red Keep whilst fighting men from the Vale.<nowiki>''</nowiki>
Niall Martell was considered charismatic amongst his piers and masters, including Oberyn Martell who was his master of arms during his younger years. Rapidly he began to surpass most of the Light Spear masters. With the skills he took years of honing, he entered the fighting pits of Dorne multiple times and was deemed victorious all the time. Oberyn decided with such skill, he began to teach the ways of dealing with multiple enemies at once with the Light Spear. He was more then successful in his studies.
For more then a few years, Niall also acted as Oberyn's Personal guard in which he would spend most of his time in pleasure houses where he would guard the doors. In most cases Niall would be offered to join his uncle but he has refused every time. He believed that such temptations should be tamed but has never refused an offer from the whores of the pleasure houses. He was considered to be highly skilful in bed and was said to be ''"Devilishly Handsome" '' <nowiki>''</nowiki>by many of the whores he laid with. In most cases he would spend hours laying with them and pleasuring the whores. For this he has never had to pay for his affairs.
A few years later he was then spotted in the Red Keep attending Michael Targaryan's Wedding with Margery Tyrell. He was with Oberyn Martell during this encounter as Quinn Martell was injured and explained that his injury was the result of Golden Company and Vale assaults in the secret passage. Oberyn Martell took an oath to bring these men to justice and took Niall with him under the tunnels with some Dornish. They fought well but during the last encounter, Oberyn Martell died from the overwhelming assaults and at the time, the cave was collapsing. Niall was the only surviver.
He is now in Braavos talking to Ziown, asking for help to bring those who are responsible to justice for murdering his uncle and disturbing the kings peace.