Monsignor Vega is a Vatican bishop who is the secret leader of the Heretical Order of the Shadows.
Order of the Shadows
As the leader of the Order of the Shadows he wishes to destroy the Library and bring back the Dark Ages by using the Cornerstones of the Library of Alexandria. When the four cornerstones were activated they opened a vortex which started to bring the Library into our dimension. His attempt to destroy the Library is stopped when Nicole Noone throws one of the cornerstones into the vortex and Vega jumps in after it. It is unknown whether he was killed after jumping into the vortex, but it appears highly probable.