When Legends Of Tomorrow was brought into the Arrowverse on the CW, it was a very bold move. For unlike Arrow and Flash before it, this was not a team set in the lore of DC Comics. The team was all DC Comics characters to be sure, but no team called the “Legends Of Tomorrow” had ever existed in the universe. Thus, it was breaking ground. However, the first season was very inconsistent. Yet, it kept going, and with Season 02 they found their niche, and it helped that they had the Legion of Doom as the villains.
This iteration of the Legion of Doom was Reverse Flash (the original Eobard Thawne), Malcolm Merlyn, Damien Darhk, and Captain Cold. Fans loved the characters separately, and bringing them together made them even more fun. And this apparently also spoke to the fun the actors were having as them. For Reverse Flash himself, Matt Letscher, revealed that each of them pitched to the CW an idea of a sitcom starring the legion.
“It was a lot of fun,” he revealed to Discussing Film. “I had a great time with those guys. And you can tell they’re having fun, too. It’s definitely one of those sets that was really easy to work on, everybody was such a pro. We pitched – multiple times — we pitched a half-hour sitcom version of the Legion of Doom to the powers that be at CW and nobody’s bitten yet, but I still think there’s a possibility.”