It's always interesting to find out about the history of K-Pop groups and the possible lineups that could have ended up becoming the group.
BTS, was actually quite different in their earlier days. In fact, the group's concept was nothing like what many people are familiar with today, as RM, Iron, Supreme Boi, J-Hope, Suga and other rappers were part of the lineup. What was meant to be a hip-hop based group somehow magically found its fate into becoming the world's most influential idol group that has made an impact on not just the history of K-Pop but the global music scene.
Below are the candidates that might have been members of BTS. Imagine this lineup plus RM, Suga, and J-Hope.
Kidoh (Former Topp Dogg Member)
SuWoong (Boy's Republic)
Atom (Topp Dogg)