Jack Kirby's Manhunter

Jack Kirby had a few last surprises for DC Comics fans in the 1970s, as First Issue Special #5 (August, 1975) hit the racks.  This issue introduced readers to lawyer Mark Shaw, whose uncle, archeologist Bradford Shaw, introduced the public defender to the organization of the Shah, an ancient order dedicated to justice....whose current member was soon to face retirement after barely defeating the Chopper (as he related to his leader, the Grand Master).  The Grand Master heard Mark's pleas for justice, and sent him a uniform and power baton of the Manhunter, which he used to defend his uncle and himself from the thugs of Al Beefer, the Hog.

But, alas, Kirby was leaving DC, and readers never saw the follow up battle of Shaw's Manhunter and the Hog...

Justice League of America

Manhunter did finally return in Justice League of America #140 and #141 (March and April, 1977), in two stories ("No Man Escapes The Manhunters" and "No World Escapes The Manhunters") by Steve Englehart, Dick Dillin and Frank McLaughlin, with Mark Shaw returning to bring Green Lantern (Hal Jordan) to justice, because it appeared he destroyed a planet full of people.  The political leader of that planet, Governor Tozad,  survived, and was leading forces of a neighboring planet against the Guardians of the Universe (one of whom was on that planet of Orinda), and that Guardian helped Green Lantern break free from the Manhunters, revealing the Manhunters to be organized on many planets, with many agents working for them (and against the Green Lanterns, including faking the destruction of Tozad's planet, which he arranged as he was also a secret agent of the Manhunters).

The Guardian of the Universe reveals that the Manhunters were originally robots they used to protect the universe, but the Manhunters proved too single-minded to work (and they rebelled against the Guardians), so the Guardians retired the robots (and started to use humanoid agents, which eventually became the Green Lantern Corps).  Both Superman and Flash related their encounters with Guardians of the Universe in passing, as Batman also mentioned how he met a Manhunter (Paul Kirk), who died fighting the Council.  The Manhunter Mark Shaw was to replace also resurfaced, and Mark Shaw lost faith in the Manhunters (who also were prepared, having a "Supermanhunter", a Manhunter with Kryptonite armor, to face Superman).  The Manhunters were a thread to the whole galaxy, but disappeared again after this encounter (though Mark Shaw stuck around, taking on the identity of the Privateer until Justice League of America #150, where he eventually was brought to justice).

Millennium and More

The Manhunters revealed in the Justice League story waited for a while, but came back with a vengeance, menacing the whole DC Universe in the Millennium 8-issue mini-series of January and February, 1988 by Steve Englehart, Joe Staton and Ian Gibson, which also crossed over into most of the titles of the time, as members of heroes supporting casts were revealed to be Manhunter agents....and, in the Suicide Squad (#9), they recruited Privateer Mark Shaw for help against the Manhunters, with him surviving the mission, thus allowing him to go free when it was over.

Manhunter Mark Shaw ended up with his own title, which lasted 24 issues, where he acted as a super-villain bounty hunter, capturing villains that would be used for the Suicide Squad (like Count Vertigo), invading aliens, the Janus Directive, along with dealing with his own issues (enhanced by shape-changing hitman, Dumas), in issues by writers John Ostrander and Kim Yale, and artists Doug Rice, Sam Keith, Kelley Jones, Mary Mitchell, Romeo Tanghal, Pablo Marcos, Frank Springer, John Koch, John Statema and Grant Miehm.

Mark Shaw survived that series, working with the Suicide Squad for a bit, then having a complex connection to other Manhunters (partially thanks to Eclipso, and Chase Lawler, Kirk DePaul and Kate Spencer)...

.....but, all of which was pretty impressive for a character created by Jack Kirby!