This is "Looks Like I'm Moving," a feature that spotlights instances of comic book supporting cast members that migrate from one title to another one.
Today, we look at Captain Boomerang's transition from being a Flash Rogue to being a mainstay member of the Suicide Squad.
Roughly a year into Barry Allen's stint as the star of the Flash ongoing series, Captain Boomerang first showed up in Flash #117 (by John Broome, Carmine Infantino and Murphy Anderson), with one of the goofier origins for a supervillain (but with an awesome costume)...
While a villain who used a bunch of specialized boomerangs as his main weapon of choice was the hook of the character (comic book people love boomerangs. Marvel also had a supervillain who is boomerang-themed. It makes you wonder, though, why the boomerang is such a villainous deal when the most famous use of the boomerang in comics is Batman's batarang), Captain Boomerang was also noted by how many outlandish death traps that he would put together against the Flash that would involve giant boomerangs of some kind. Really, the good Captain likely spent most of his spare time building giant boomerangs to try to kill the Flash. He barely had time to rob banks as he was far too busy building giant boomerangs.
I once did an article about the "team effect," which is the effect when villains who were once able to take on a hero or a heroic team by themselves suddenly stop being viable solo villains when they join a supervillain team. It happens all the time in comics and Captain Boomerang was a notable example of this effect when he and a few of Flash's other mid-level villains got together and formed the loosely affiliated supervillain team known as The Rogues...
This was a tough situation for Boomerang, because on the one hand, the Rogues were awesome. They were great. They would appear frequently as Flash villains. On the other hand, once you are seen as a "team" villain, it is a lot harder for anyone to take you seriously as a solo villain again. Thus, Captain Boomerang made relatively few appearances as a solo villain once he joined the Rogues, although he did have a notable appearance as a Batman villain.
Okay, so Crisis on Infinite Earths happened and suddenly, Barry Allen is dead. Wally West takes over as the new Flash. For whatever reason, the newly relaunched Flash series spotlighting Wally West had little interest in the Rogues. I still don't get the exact reasoning, but for whatever reason, the Rogues were considered passe. I once wrote about how DC seemed to go out of their way in the late 1980s to make their Silver Age villains look like a bunch of dopes. That was too bad in general, but it worked wonders for Captain Boomerang.