If the weak premise wasn't bad enough, Valiant's and Image's writers knew nothing about the other company's characters, resulting in a ton of
Character Derailment, even though most of Image's side barely qualified as "characters" to begin with. The art, done in the over-the-top Image style, was disgusting to behold, and to top it all off, Deathmate may have been responsible for
The Great Comics Crash Of 1996.
You see, Valiant (as a byproduct of its unique real-time continuity system) was super serious about shipping schedules and deadlines, and produced all its contributions on time. Image on the other hand was notorious for its
Schedule Slip, so, the Valiant half of Deathmate was produced on time, but the Image half was produced late. (
Rob Liefeld produced his contribution a year late, and only after the editor in chief of Valiant Comics came to his house, refused to leave until it was done and inked it in a hotel room.)
By the time the Image half came out, interest in it had dried up, but shop owners had pre-ordered massive numbers of issues when the cross-over had started, and were now left with mountains of unsellable comics. This, more than anything, contributed to the collapse of the comic industry in the 90's. Deathmate was also one of the events that lead to the fall of
Valiant Comics, as it flooded the company with Image artists, and caused a fundamental shift in the way the company was run.
The advertisement for
Deathmate said "Their love will end worlds!" While it was talking about Solar and Void, it could also be said to be true of Valiant and Image. This disastrous "pairing" did indeed destroy worlds: It destroyed the world where the comic book industry makes $500 million per year.
It destroyed the world where
Valiant Comics so much as existed, much less was the third highest selling comic company. And it destroyed the world of small comic book shops, many of which went out of business.