34 years ago - Danton Black is born.
16 years ago - 18-year-old Danton goes to college studying particle physics.
10 years ago - 24-year-old Danton Black is paid by Henry Hewitt to sabotage Martin Stein's Nuclear Matrix reactor experiment. In the resulting explosion, he is hospitalized.
9 years ago - 25-year-old Danton Black recovers in the hospital, discovering his ability to split himself into duplicates. He becomes the criminal and mercenary, Multiplex, battling Martin Stein & Ronnie Raymond's Firestorm.
7 years ago - 27-year-old Danton Black assists Henry Hewitt in kidnapping Lorraine Reily to force her father, Senator Reily, to sign the Hewitt bill. He is finally stopped by Lorraine when she becomes Firehawk, and is sent to prison.
5 years ago - 29-year-old Danton Black escapes the Suicide Squad after the death of Rick Flagg. He is caught by Wally West and sent back to prison.
2 years ago - 32-year-old Danton Black is freed from prison by President Lex Luthor to attempt to capture Superman while he is a fugitive. He manages to escape by posing a duplicate as his prime body.
You really have to give it to the creative team of the original Firestorm comic. Gerry Conway and artist Al Milgrom were just swinging wildly at every pitch and what came out of that book is something that could only ever work as a comic book. Even the villain of that first issue, Multiplex, is a burst of weirdness that honestly shouldnt have worked, but he's still around today, serving as a very very servicable antagonist for a wide variety of DC heroes.
Multiplex's Comic History
Multiplex first appeared in Firestorm volume 1, #1... making him the first actual Firestorm villain. The entire series is such a madcap rush of comic book quirkiness and this character was no exception. Firestorm's entire premise is built in such a way as to give characters completely impossible power sets without ever having to explain how they were happening. Multiplex was, simply, a dude who could endlessly replicate himself.
This first issue was really the only time he ever showed up wearing this weird cape-and-helment ensemble. From here on out he appeared in a skin-tight jumpsuit more befitting a character the artist would have to draw a dozen times in every panel. Where there are absolutely stories where he carred an arc as the main villain, his main utility in the years that followed was as an excellent eddition in team books. He would of course always be on hand whenever Firestorm villans worked together, but you'd also occasionally see him work with Flash Villains, as a long-standing member of the Suicide Squad in the 90's, and as a recurring member of the 90's Legion of Doom and Secret Society.
Our Multiplex Story
There really aren't a lot of super-standout Firestorm villains; essentially just Multiplex, Tokamek, and of course Killer Frost, so it becomes very easy for us to tie him more directly into Firestorm's backstory. Given that the core concept of Firestorm is two people combining into one, there's a certain synergy to the idea that the second person caught in the same blast wound up with the exact opposite powers.
Moving forward, our main use for Multiplex is in stories where he's fascilitating another villains goals. whether it's working alongside Tokamek, or as a hired gun working for President Luthor to bring in a rogue Superman, or as part of the new Legion of Doom, Multiplex's journeyman powers make him a cool character that we can always add to the mix.
Of course, we also added him into the Suicide Squad, if only briefly. He's just one of those baddies that don't really require a lot of work to bring into the world, and once he's there, he's a great tool you can always use to advance almost any story you're trying to tell.