Montague Castanella is an in-game professor in Steel Canyon University as well as the leader of the clandestine group known as the Midnight Squad. Heroes are first contacted by Castanella when they reach security level 10.
Very little is known about the college professor named Montague Castanella, and part of it is by design.
As the leader of the Midnight Squad, he relishes the covert nature of the organization, which has allowed him to keep the secret of his own mystical ability intact. In addition to his expertise in Ancient Roman culture, Professor Castanella posseses the unique ability to detect shifts in the fabric of time and space. This ability became far more profound after the Menders of Ouroboros began contacting heroes and villains and the Professor began to notice huge shifts in the space-time continuum.
Deciding the time was right, Castanella sends the message out to the heroes of Paragon City to see him as soon as possible. Likewise, his associate Ashley McKnight starts reaching out to the villains of the Rogue Isles.
Montague Castanella appears in Issue #8 of the two-part "Limelight" story for the "Guardians of the Dawn Spotlight" series where he converses with Lord Lee Geddy. Both warn each other of the knowledge of their respective clandestine organizations.
(See his Paragon Wiki entry for more information.)