Mail Jeevas, who is more commonly known as Matt, performs espionage work for Mello. Little is known about this character aside from the fact that he doesn't care much about the real world and likes to play video games. He acts as an accomplice to Kiyomi Takada's kidnapping and is shot dead by her bodyguards. He smokes a cigarette with his last breath, leading to the speculation that he might very well be a chain smoker.
Quite an impressive cosplay of Matt. I'm not sure what the watermark "NadesicoRock" means, but I do hope that's the cosplayer's alias. Thanks for sharing this wonderful work!