When the Lady Vampire Elder Amelia, her entourage from the New World Coven, and her advisors, the Vampire Council, are long past late in arriving at Ördögház, (to unite with the Budapest Coven for the centennial Awakening Ceremony to shift the transfer of power over the Vampire Nation from Lady Amelia to Lord Marcus), Mason is asked by Kahn to "slip off the property and find out what's keeping her", (as he does not trust Kraven anymore).
Later, Mason and at least two other Death Dealers, arrive at the private train used to transport Amelia, only to discover that she, her attendants and the entire Vampire Council inside have all been slaughtered by Lycans, due to the treachery of Kraven. Upon discovering the massacre, disturbed and appalled, Mason speed dials Ördögház to appraise Kahn of the situation.
Mason makes an appearance in the non-canon novel, Blood Enemy, where he is a part of operation to kill a 'rabid' She-Lycan, Leyba, after she killed a Death Dealer named Diego. Mason was assigned to Selene's team, who are to infiltrate the compound to kill Leyba, while Kahn's team keep Leyba attention at the front of the estate. During the mission, Yoshio, the other member of their team inadvertently triggers a booby trap inside the estate's dining room, triggering a series of internal UV floodlights. Selene and Mason are both able to take cover under the dining room's heavy set mahogany table, while Yoshio, trying to escape the UV light through a door, triggers another booby trap, a bomb. Mason is wounded and unable to go on and so tells Selene to go on with the mission without him.
- Mason is played by Danny McBride, one of the film's three writers.
- Samantha, the late-fiancee of Michael Corvin, is played by Danny McBride's wife, Ilsa.
- In Mason's appearance in the non-canon novel Blood Enemy, he was described as an American Death Dealer.
- "I'm alright," the American Vampire answered. "I took a couple pieces of shrapnel, in the back and in my hip, but nothing a little blood can't fix." ~ Blood Enemy novelization, chapter 21