Deathmate

Deathmate was a six-part comic book crossover between Valiant Comics and Image Comics published in 1993 and 1994. 
Background.
Designated by color rather than issue numbers (namely Yellow, Blue, Black, and Red) plus two book-end issues, "Deathmate Prologue" and "Deathmate Epilogue", as well as Preview issues collected with comic products, the four main issues were written so they could be read in any order. Created at the peak of the comic book speculator boom, the project was heavily promoted and sold hundreds of thousands of copies, but was beset with production delays. The Image half (Black, Red, and Epilogue) came out severely behind schedule and out of sequence. "Deathmate Red" shipped after the epilogue issue, and despite cover dates of September 1993 to February 1994, the actual publication lag was far longer than six months.
The plot evolved around a chance interdimensional meeting of two characters, Solar from Valiant and Void from Image's WildC.A.T.s. The two became lovers, but their joining would mean the destruction of both comic book universes.
It is notable that only half of the Image founding members chose to take part. Erik Larsen, Jim Valentino, and Todd McFarlane were not involved, although McFarlane's character Al Simmons makes a brief appearance in "Deathmate Red".
Synopsis.
In a world that had been long since become a terrible place, Solar reluctantly granted the wish of his lifelong companion, Gayle Nordheim to dissipate the lifegiving energy that had kept her alive and young for so long. So unable to contain his grief by her passing, Solar was literally split in two. The remaining Solar vanished into a life of seclusion while the new persona went off to find other planes of reality to explore.
There, in a dimension between what is real and unreal, he encountered a creature of incredible power, a woman from a distant universe, Void. The two fell in love, a love that wound end all time literally. Upon consummating, their combined energies fused, unwarpping the fabric of time, spiraling backwards and eating away at their distinct timelines. In an instant, things were not as they should be: heroes fought alongside those who had been their enemies in a different world; great men who would bring justice to the world died horrible, untimely deaths. Only men with the gift of foresight, Geoff McHenry and Prophet, knew that all was not as it should be. Where they had seen a future so clearly before, there was now nothing.
Geoff and Prophet are resolved to gather the heroes of this amalgamated universe together to fight the battle to save all time.
The books.
Preview Issues
Green
sold with Comic Defense comic bags or Advance Comics magazine
Same story and cover, but with the logo of the sponsor in the corner
Story: Solar and Prophet battle Erica Pierce
Orange and Pink
sold with Previews magazine
Same story, but different covers
Story: Archer chases Shadowman while Grifter chases Archer
Books from Valiant
"A Love to End All Time"
Story: Bob Layton
Pencils: Barry Windsor-Smith
Inks: Jim Lee
"Universal Truth"
Story: Bob Layton
Pencils: Rob Liefeld
Inks: Bob Layton with Danny Miki and Dan Panosian
"Jerked Through Time" (featuring characters from "Archer & Armstrong" and "WildC.A.T.s")
Story: Mike Baron
Pencils: Bernard Chang
Inks: Rodney Ramos
"Cat and Mouse" (featuring characters from "Ninjak" and "WildC.A.T.s")
Story: Jorge Gonzalez.
Pencils: Don Perlin
Inks: Mike Manley
"The Dying Game" (featuring characters from "H.A.R.D. Corps" and "WildC.A.T.s")
Story: David Michelinie and Bob Layton
Pencils: Mike Leeke
Inks: Tom Ryder
"Revelations and Recruitments" (featuring characters from "Shadowman" and "WildC.A.T.s")
Story: Bob Hall
Pencils: Mark Moretti
Inks: John Dixon
"Battlestone vs. Magnus Outlaw!" (featuring characters from "Brigade" and "")
Story: John Ostrander
Pencils: Jim Calafiore
Inks: Ralph Reese
"Secret Forces" (featuring characters from "Secret Weapons" and "Cyberforce")
Story: Joe St. Pierre
Pencils: Sean Chen
Inks: Kathryn Bolinger
"Sacrifices" (featuring characters from "Harbinger", "Brigade", and "Cyberforce")
Story: Maurice Fontenot
Pencils: Howard Simpson
Inker: Gonzalo Mayo
"Supremely Darque" (featuring characters from "Solar" and "Supreme")
Story: Kevin VanHook
Pencils: Peter Grau
Inker: Jimmy Palmiotti
Books from Image
Story: Brandon Choi and Eric Silvestri
Pencils: Brandon Peterson, Brett Booth, Marc Silvestri, J. Scott Campbell (as Jeffrey Scott),Scott Clark, Greg Capullo, Jim Lee, and Whilce Portacio
Inks: Scott Williams, Sal Regla, Alex Garner, and Trevor Scott
Story and Pencils: Rob Liefeld
Script: Eric Stephenson
Additional pencils: Jeff Matsuda, Rich Horie, Dan Fraga, Cedric Nocon, Dan Pacella, Anthony Winn, Marat Mychaels
Inks: Danny Miki, Jon Sibal, Marlo Alquiza
Story: Bob Layton
Pencils: Marc Silvestri and Joe Quesada
Inks: Bob Layton and Scott Williams
Reading Order.
Despite both publishers saying the issues could be read in any order, fans have long speculated that there must be a proper order as the story doesn't make sense. In December 2017, a Reddit user and member of the Valiant Fans forum claimed that he had solved the dilemma and suggested that there is, in fact, a reading order where the story is more coherent. The proposed order is:
This proposed order is wildly different from the order in which the issues were published. It's based on the content within the books and the timeline in which events must occur in order for a non-contradictory, cohesive narrative to exist. Deathmate was long considered "uncollectable" due to it having no proper order, and largely being viewed as unreadable by fans, but this new proposed order potentially solves that problem. Regardless, a collection seems unlikely as the character rights are now spread across several companies, with Solar, Magnus and Turok having been licensed to Dynamite Entertainment and the Wildstorm characters now being owned by DC Comics.
Aftermath.
Although the issues of "Deathmate" produced by Valiant shipped on schedule, those produced by Image Comics did not, a problem that Image faced with many of its publications in its early years. The books were pre-ordered in heavy quantities by retailers, and when shipping dates were not met, distributors cancelled the original orders and required re-orders. By the time the last issues did arrive, some fans had lost interest, leaving retailers with unsold copies.
As a cross-promotion, two trading card companies also did a cross-over, Upper Deck and Topps. But, because of the deadline problems with Image Comics, Topps ended up backing out of the contract.
In a retrospective interview on the rise and fall of Valiant, Bob Layton (former editor in chief) lambasted the whole affair, regarding it as an "unmitigated disaster." Layton says he had to fly to Los Angeles and literally sit on Liefeld's doorstep until Liefeld finished his penciled art for the "Deathmate Prologue", and then Layton inked the artwork himself in an Anaheim hotel room. Layton stated, "What a pain in the ass that was! There I was, with my own company to manage, and I was in California, managing someone else's people. I look back at it and can't believe some of the shit I had to put up with as E.I.C. of Valiant. As far as failures, Deathmate and [Valiant promotion] Birthquake were unmitigated disasters. Not necessarily in the numbers, but in the consequences of their release...I think that Deathmate sounded the beginning of the problems, and when Image couldn't get their side of the cross-over out on time, it hurt everyone. I think [Valiant crossover] Chaos Effect the next summer was a decent idea, but there wasn't anything new to capture the audience's imagination. We made a specific mistake in choosing not to advertise during the summer of '93. Our books were almost too hot and we wanted to get more realistic numbers. Remember, we were the collectible company. That meant wealthier speculators buying cases of the stuff, hoping to sell it for ten times what they paid for it within a year. In some cases, they did! That's why there's so much of our output from that era on the market."
"I literally had nothing to do with most of those projects," Layton revealed, "Deathmate was thrust upon us because (Steve) Massarsky and Jim Lee were best buddies at the time and had privately arranged the crossover."
For retailers, "Deathmate" was harmful, due to the tying up of cash flow with books arriving late, especially given the $4.95 USD cover price (at the time, the average comic book cover price was less than half of that). Also due to waning fan interest, the re-orders were lower than initial orders. The Valiant "Deathmate" books (Prologue, Blue, and Yellow) had print runs of over 700,000 copies, but by the time "Deathmate Red" was released, it had a print run of 250,000, although retailers were nonetheless left with many unsold copies. At the time, comic book distributors would only allow unsold books to be returned if they were six months late. Retailers dealt constantly with late books from Image, which indirectly caused some comic book shops to close. Partially due to the lateness of Image publications, the window was eventually decreased to two months.