The XX or simply The 20 are a fictional organization in both the XIII comic and game.
The XX was most likely formed by Number I with help from various other people as a patriotic militia. Sometime after its creation, they began to recruit other like-minded and politically powerful individuals and with the help of William Standwell, took control of SPADs (Special Assault and Destruction Squads) turning them into mercenaries under the employ of the Mongoose. After several years of careful planning, they decided to strike against the Government.
An infamous hitman hired by The XX to carry out assassinations and other evil deeds. The Mongoose is a cruel and cold-blooded murderer who carries out his orders with eagerness and glee. He commands an army of hitmen to do some of his dirty work. He is aided by his assistant Irina Svetlanova.