In Mega Man ZX, what is the name of the main villain?

In Mega Man ZX, the main villain is Serpent. He is the Reploid leader of Slither Inc., an energy-development and private-security company that appears to be helping maintain peace between humans and Reploids.

Serpent’s public role hides his real objective: he seeks the power of Model W, a dangerous Biometal linked to the mysterious incidents causing Reploids to go Maverick. He manipulates events and uses Slither Inc.’s resources to pursue that power, eventually confronting the game’s protagonists directly.

Model W is not Serpent’s name; it is the central artifact he wants to control. Pandora and Prometheus are important characters in the Mega Man ZX storyline, but they are separate antagonists and not the game’s primary villain. Mega Man ZX was released for the Nintendo DS in 2006 and continues the world established by the Mega Man Zero series.