The Cleaner

 was a highly skilled assassin hired by Louis Bouchard to kill Lara Croft during the events in Tomb Raider: The Angel of Darkness.

He was a specialist assassin who used modern devices and weapons such as bombs, trip lasers and sophisticated firearms to hunt down and kill his targets.

Mission
He attacked Lara in Von Croy's Apartment in an attempt to kill her with his highly powerful Viper machine gun. She managed to escape him briefly until he shot down a wall and proceeded again to attack her with his pistols as he had run out of ammo for his Viper, Lara again managed to make him flee to safer position and she then picked up his Viper, for which she had gathered ammunition. The entire building was filled with bombs and trip lasers that he had placed, in case. When Lara tried to escape, he had destroyed, with a bomb, a stairwell in attempt to kill Lara. When Lara was trapped at one end of a long corridor, The Cleaner was on the other side, and a huge amount of trip lasers between them both. He kept on firing at Lara to eventually finish his mission and turned off most of his lasers so he could get an clean shot, but then Lara managed to use his own Viper and fired at him. He was shot multiple times in the chest and fell down the stairs until he landed with a sickening thud on the floor, finally dead.

Trivia

 * It is never revealed what his real name actually is.
 * He doesn't appear to be a member of The Cabal; He only seems to be an assassin hired by Louis Bouchard, but this is unclear.
 * His artwork (Seen above) depicts him with the M-16 assault rifle (Instead of his Viper SMG), which is not used in-game.