Linear Authority Dossiers:
Hayden Glass - Shapeshifting killer of the 22'nd century. He is the son of a super-hero who abandoned his family, and was born with the metagene, possibly due to a Cadmus experiment. He can alter his appearance to look like anyone he chooses, but can only change back to his normal self either after killing someone or by being given an electric shock. He killed hundreds of people in Metropolis by appearing to be family members, which baffled the police. He also went on a killing spree in Star City, committing one murder in the guise of each of the original Justice League. He was apprehended by Walker in 2113 in Star City. He later escaped his cryogenic prison in Belle Reve in the 23'rd century, and attempted to kill Walker before he became Chronos, but was defeated by a future version of Walker Gabriel. Walker then left Glass by himself in the Jurassic period.
Gravesend - A corpse-like creature, Gravesend is the one who runs Chronopolis. He served the last of a celestial race long ago in another space-time continuum, and when their universe was annihilated, he was transported to another to continue their work. He appears to know a great deal about Walker Gabriel's destiny.
Rip Hunter - Time-travelling adventurer. He was a pioneer in time-travel in the 20th century, discovering several possible methods. He was stranded for a while in prehistoric times, and was rescued by as yet unknown means. He is currently a member of the Linear Men, and was one of its founding members.
Mordechai - Robotic companion of Fiorella Della Ravenna when she resides in Chronopolis.
Konstantin Vyronis - A ruthless scientist wishing to make all of time bend to his iron will. In the initial time-line he tricks Walker into helping him, causing Vyronis to gain power equal and beyond the guardian's power. Soon after, Walker managed to merge himself with his past self and destroyed Vyronus's evil invention. Regardless, Vyronis is a manipulator who can bring the soft of will over to his side.