Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled.
Cuchulainn (クフーリン,Kufūrin?) is one of the 10,000 players who were trapped in «Sword Art Online» and a member of the Legend Braves, a team, formed for a virtual reality game three months before the release of Sword Art Online, who decided to play Sword Art Online together.
On December 8, 2022; Cuchulainn and his friends were spending the evening in a bar when Nezha joined them. They began conversing about Nezha's business, but stopped when they noticed that the door looked suspicious.
The next day, Cuchulainn, along with Orlando and Beowulf, took part in the battle against the Bullbous Bow as the reserve. After two of the tanks were hit by the Field Boss and were temporarily unable to continue the fight, Kibaou gave the signal for Beowulf and Orlando to replace them.
On December 14, 2022; Cuchulainn, along with Orlando, Beowulf, Gilgamesh and Enkidu, joined the raid party for the 2nd Floor Boss and formed group G. Initially, they were supposed to be one of the two parties assigned to dealing with Nato the Colonel Taurus, but as they had lost contact with Nezha and thus lost a significant source of income, they managed to persuade Lind to allow them to fight against Baran the General Taurus instead.
Later, when Argo informed Lind and Kibaou about Asterius the Taurus King's patterns, Cuchulainn and the Legend Braves proved to be the strongest group in the raid, as they could withstand the numbing effects of the boss at very close range without being stunned due to their high debuff resistance armour and could thus continue their assault even when the taurus used his numbing skill, while all the other attackers had to temporarily retreat.
In the aftermath of the battle, when several players of the raid who were scammed by Nezha approached the former blacksmith to hear his explanation, Cuchulainn and the group stood at the left edge of the raid, visibly uncomfortable. The group continued watching and whispering to each other as the crowd became angrier. When the crowd began demanding Nezha's death, the group stared down at the ground, avoiding looking at Nezha, until they decided to approach Nezha. Unexpectedly, they got next to Nezha and admitted their involvement in the fraud.
Sword Art Online
Cuchulainn's name is based on a Celtic legendary hero.