Sai Yukitsugu

Itsuki (イツキ) is an original Sword Art Online game character in Sword Art Online: Fatal Bullet. He is one of the most famous and top skilled players in Gun Gale Online (GGO) and is the leader of the Squadron "Alphard". While he is seemingly a calm and carefree player, Itsuki is secretly on a constant search for something to excite him. This obsession leads him to become the main antagonist of Fatal Bullet.

Gun Gale Online
Itsuki has a red and narrow eyed avatar with dark grey hair. His outfit prominently features black and white, a light blue on the inside of the arms of his long tailed coat, with red seams overall. He carries gun shells on the side and back of his coat. His canon choice of weaponry is a Dragonfall that resembles a real life Dragunov Sniper Rifle as his primary and a Sirius Optical Sub-Machine Gun as his secondary.

Personality
Itsuki is a mysterious character, who is never willing to share anything regarding his real personality. Instead of being an open character, he enjoys providing various information about himself and promptly follow up by claiming that he was kidding. Other than that he is a skilled leader and a genius player when it comes to laying decoys and traps in GGO, even his Squadron members do not know much about him.

Towards the end of Fatal Bullet, Itsuki opens up to to the Protagonist first. He explains how boring he feels and the only thing in the world that sparks his heart is them. In the final chapter of the game, he admits that he desperately longed for their utmost friendship and that he did not care for anything who would be a threat to that, going as far as coming up with a devious plan that could kill himself, the Protagonist, Kureha and Zeliska.