Argen is part of Division V, but has never really felt comfortable there. Argen's job is to raise funds for the NEXUS, and so he fulfills the classic sales job in an organization that actually has no sales.
Stupidly, Argen is also the one who released GLADIUS into freedom. However, he has successfully kept this point a secret to this day.
Overall, Argen is a bit too uppity for his accomplishments. However, when it comes down to it, you can actually rely on him.