Supporters of popular comic book properties tend to be vocal about their ideas for where stories should go, now moreso than ever due to social media. As such, it is interesting to see that there have been instances in which fans have been able to make meaningful contributions to storylines. One of the more unique instances of such pertains to Superboy, as a shocking twist in a run of Teen Titans was suggested by a fan nearly seven years before it came to fruition.
In April 1996, a fan letter was published in an issue of Superboy from someone that fans of the character are very familiar with -- Geoff Johns.
Superboy made his debut in 1993, in The Adventures of Superman #500 (By Karl Kessel and Tom Grummett), and has since become a fan-favorite character. Following Superman's death at the hands of Doomsday, Project Cadmus director Paul Westfield wanted to create a clone of Superman. Unable to acquire Superman's DNA, Westfield altered a human clone, making him as close to Kryptonian as possible. After many failed attempts, Cadmus successfully created a teenage clone, implanting him with Superman's memories.
In years following, the character would develop into his own. After Superman's return, the two developed a bond, with Superman even considering Superboy to be family, giving him the Kryptonian name Kon-El. He operated on his own for a period of time, and would go on to become one of the founding members of Young Justice, and eventually a Teen Titan.
In 2003, Superboy's origin was retconned, and at the end of Teen Titans #1 (by Geoff Johns and Mike McKone) we learn that he is the half-Kryptonian, half-human clone of Superman and an unknown donor, who is revealed to be Lex Luthor. The revelation changed the course of stories that followed, with Superboy struggling with the fact that he could either become the world's greatest hero or villain.
What most fans don't know about this plot point, however, is that Johns had this idea for years leading up to the revelation. In a message printed in the pages of Superboy #26 in 1996 (by Karl Kessel, Steve Matteson, and Staz Johnson), a 23-year-old Johns wrote to the comic book, theorizing that Superboy could potentially be a clone of Superman's greatest villain. He also stated that the concept could have interesting ramifications for the future; however, the idea was shut down in the response to his letter.
It is interesting to see that seven years later, Johns was able to join the company and incorporate the idea into his sustained run on Teen Titans. This origin for the character has since become the most popular. The storyline even made its way into the first season of Young Justice, as well as Titans, having a similar impact on the character's development.
Following his run on Teen Titans, Johns would go on to impact the DC universe in a huge way, penning memorable titles such as Infinite Crisis, Flashpoint, Justice League, and Doomsday Clock. Although he started off as a passionate fan, Johns was able to take his idea and create one of the most notable aspects of the Superman mythos, going to show that ideas from comic book readers can and do turn into interesting storylines.