Crisis on Infinite Earths (1985) was meant to clean-up continuity by killing off a bunch of worlds/characters, and the goal of the the LEGENDS mini-series (1986) was to re-establish and strengthen the iconic characters/teams that remained (and even create new ones). Seeing as how LEGENDS was the second big company-wide cross-over, most major titles at DC comics had to have a part in LEGENDS, and the Cosmic Boy mini-series was the Legion of Super-Heroes’ contribution. Sales for Legion of Super-Heroes were starting to show a bit of decline in 1986, and any promotional gimmick to draw in new readers would’ve been applied.
The Cosmic Boy mini-series is a spin-off of LEGENDS in the truest sense of the word; you actually need to have read LEGENDS #1 and #2 (before reading Cosmic Boy #1) in order to understand what’s going on. During his brief appearances in LEGENDS he makes references to a few things that wouldn’t make any sense to a reader unless they’d been reading the Legion of Super Heroes ongoing series for the last year and a half.
This mini-series occurs sometime between Legion of Super-Heroes v3 #23 (last appearance of Cosmic Boy and Night Girl leaving on vacation) and Legion of Super-Heroes v3 #36 (Cosmic Boy and Night Girl are shown recuperating from trip). Prior to this, the Legion of Superheroes had just received an influx of new members in Legion of Super-Heroes v3 #14 (thanks to Paul Levitz and Steve Lightle) and Saturn Girl, Lightning Lad and Cosmic Boy had decided to retire from active duty. I’m going to guess it’s because the writers wanted to focus on the new characters and needed a plausible reason why the original three legionnaires were nowhere to be found. I really feel for Paul Levitz, I really do. At any given time the Legion of Super-Heroes has at least 20 active members and they all have to be doing something that will move the plot along in some way.
Paul Levitz wrote this mini-series and makes a valiant attempt to address the whole ‘Superboy/Legion of Super Heroes’ paradox that was created by Crisis on Infinite Earths (hint: blame it on the Time Trapper). Levitz also tries to explain why the Legion of Super-Heroes’ peaceful pre-Crisis future doesn’t sync up with the post-Crisis future (even using modern examples from 1986 such as the space shuttle Challenger disaster and the Chernobyl nuclear reactor meltdown). This is a very good example of a writer (Paul Levitz) being flexible and able to think on his feet by managing to tie past, current and future events into a neat little bow.
I think bigger things were planned for Cosmic Boy (in relation to his appearance in LEGENDS), but the idea never took off. While he may have powers on par with Marvel’s Magneto, I always found Cosmic Boy to be the least interesting of all the Legionnaires. When Levitz took over the Legion of Super-Heroes in the early 80s, Cosmic Boy was portrayed as a whiny pansy who was extremely dedicated to his job. I feel that the Legionnaires only work well as team unit (for storyline purposes), and no single Legionnaire can hold the DC fan base’s attention long enough to have an ongoing series*. (Mon-El/Valor would go on to prove me wrong in 1992, but he’s basically became a Superboy substitute – and we all know that Superboy can sell a comic.)
*It should also be mentioned that Karate Kid had an ongoing series in 1976 that lasted 15 issues.
The Legion Omnicom is a Legion of Super-Heroes fan site I really enjoy reading, and if you are also a Legion of Super-Heroes fan then you should check it out.