The graphic novel will reprint work from top creators including Steve Ditko, David Lapham, Steve Englehart, Bob Hall, Bob Layton and Jim Shooter.
"Jack Boniface nearly died one night - attacked by something out of a nightmare. But since that terrifying experience something has changed. Now, when darkness falls, a feeling comes over him, an urge to destroy the demons that would defile his night," reads the Valiant solicitation.
"Wild, reckless, and hell-bent on eliminating evil in all its forms, Jack is now his city's new protector - the nocturnal avenger simply called Shadowman."
The book collects Shadowman (1992) #0-7 and material from Darque Passages #1.
Shadowman was recently relaunched as the fifth title since Valiant's 2012 relaunch.
Valiant Masters: Shadowman vol 1: Spirits Within will be released in May, with a preview released on Free Comic Book Day on May 4.