After Waverider altered his own timeline, a new reality came into existance. A new reality where Monarch never reached power but where he also was a scientist interested in time travel. In this new future, Matthew had the help of Rip Hunter and Liri Lee. Together they traveled to a point in the far future to a place called the Vanishing Point the last point in time. From this point Ryder founded the Linear Men, self appointment guardians of the continuun.
His first recruit would be surprising for him as his own doppelganger, Waverider.
The Dominus Effect
Superman, Matthew and the other Linear Men fought against Dominus.