Legion

Legion (レギオンズ) is the governing body of the whole world in Mega Man ZX Advent. This coalition government is ruled by three leaders known collectively as the Sage Trinity: Master Thomas, Master Mikhail, and Master Albert.

Master Albert is the main antagonist in the game. Using his position, Albert gave his DNA to "Chosen Ones", enabling them to Megamerge. When Ashe/Grey discovered Albert was behind the Game of Destiny and Biometal Model W, Albert leaves Legion's headquarters and goes into hiding to proceed with his plans.

Legion created the global law that brings equality between humans and Reploids, giving humans mechanical parts (becoming Humanoids) and Reploids lifespans. The original human parts and Reploid data are stored by Legion. In the secret ending from Mega Man ZX Advent, Master Thomas is shown to plan to use the stored parts and data for unknown reasons (although the arrival of the Mega Men Siarnaq, Aeolus, Thetis, and Atlas immediately after Thomas reveals this to Mikhail implies they were related somehow to his plans on the matter).

Legion HQ
Legion HQ (レギオンズ本部) is the headquarters of Legion. The area becomes available after repairing the Train. When Ashe/Grey arrives to the area to deliver the Biometal Model A, it is attacked by Mavericks. After defeating Siarnaq, it is discovered that Albert is behind the attack and Model W. Albert then escapes and begins to put his plan into motion.

Trivia

 * The Legion HQ is remarkably similar to Neo Arcadia in terms of architecture.
 * In the Legion HQ area part 1 entrance, there are road signs reading C02 and C03 that imply the Legion HQ may be located in or near Area C-2 and C-3 from Mega Man ZX.