Nicholas The Renegade

Nicholas The Renegade (背教者ニコラス) is the Christmas Flag Mob that appears on Christmas Eve under a certain fir tree in the Forest of Wandering in Sword Art Online. It has four health bars, wields a giant battle axe, and was also the first event boss who did not appear during the closed beta test, so information about him was limited.

Appearance
Nicholas The Renegade looks like a ridiculous and ugly version of Santa Claus with a pale blue face with yellow-white hair. It has red eyes that look two different ways, and has a spiky mustache and beard.

Red-nosed Reindeer
It appeared on Christmas Eve of 2023, on the 35th Floor in the Forest of Wandering. Rumors had spread a month earlier that if it was defeated, it would drop an extremely rare item that would be able to revive a player from death; as such it was sought out by many.

After the demise of the Moonlit Black Cats, Kirito learned about the boss event from Argo. He accepted the quest event and trained desperately in order to obtain the item in hopes of reviving Sachi, and, at very the least, to clarify the last words said to him right before she died.

After finding the boss, and a fight that almost results in his death, Kirito finally obtains the item, the Divine Stone of Returning Soul. However, Kirito was distraught by the fact that it could only be used to revive a player if he or she died within ten seconds before the activation of the item. Returning with a dead look in his eyes, he gave the item to Klein and his guild, who earlier followed him and held off the Divine Dragon Alliance guild to allow him to fight and defeat Nicholas The Renegade alone.

Trivia

 * Nicholas The Renegade is one of the few bosses (others being The Gleam Eyes, The Fatal Scythe, and Heathcliff) who was nearly able to kill Kirito, depleting his health to a mere sliver.