After months of lead up and cross-promotional events, DC's Legends of Tomorrow is finally premiering on The CW, a mid-season addition debuting as the other shows in the shared DC universe return from their winter hiatus. This comic book adaptation is the third installment in the genre network's run of superhero shows that began with Arrow in 2012 and continued with spinoff The Flash in 2014. While its predecessors follow the crime-fighting exploits of one central superhero - Oliver Queen/The Green Arrow (Stephen Amell) and Barry Allen/The Flash (Gustin Grant), respectively - Legends centers around an assortment of heroes and villains, many of whom have already been introduced to audiences through its sister shows.

This premiere is exciting not only because it looks like a madcap time travelling adventure, but because its launch means that Arrow and The Flash can finally stop dedicating so much time and plot to laying the groundwork for the spinoff, and start focusing on the fundamentals of their own shows again. Both have been strong in their 4th and 2nd season, but the Legends buildup has taken a creative toll on both.

Before The Flash premiered it was an anticipated show, but tinged with a "wait and see" attitude as viewers determined if Barry Allen's adventures could capture the same quality storytelling that made Arrow such a hit. Comparatively the build up and promotion leading to Legends of Tomorrow has been enormous, beginning in early 2015 and continuing nearly unabated. Now we are in the midst of the comic book adaptation boom dominating TV, and the executive producers in charge already have a proven track record for success. This spinoff was met with such excitement and enthusiasm that each development was publicized and met with fanfare - to the detriment of the other shows involved.

As each casting announcement was made they brought with them unavoidable spoilers, since the stars of Legends of Tomorrow are comprised of major players from both Arrow and The Flash. The plot twists that eventually accumulated in this unlikely team up would have been both shocking and fun, had there not been months of speculation leading up to the action, taking much of the thrill out of the story. We saw this most clearly with Caity Lotz signing on to the show, immediately sparking speculation of late Sara Lance's return and the eventual Lazurus Pit resurrection reveal. When this finally played out on Arrow, no one was surprised when Laurel dug up Sara's remains, and no one invested in her return since it was just a matter of time before she left the show (again). How much more shocking would this twist have been if viewers didn't already know her end destination?

These developments have also lowered the stakes dramatically for storylines involving actors tied to Legends of Tomorrow. Ray Palmer (Brandon Routh) could never really pose a threat to Oliver and Felicity's relationship, or run Palmer Technologies long term, since it was widely known that he would be a huge part of Legends. This aura of futility similarly hung over Cisco and Kendra's fledgling relationship on The Flash. The two could be friends who kiss all they wanted, but everyone already knew Hawkman was on the way, and the two would not be staying in Central City. Arrow has had its fair share of fake-out deaths before, but none more halfhearted than blowing up Ray in the season 3 finale. It was just a matter of figuring out the 'how' with their characters maneuverings, never the 'if'.

The Legends of Tomorrow world building culminated in the Arrow/Flash crossover event that attempted, in two episodes, to show Kendra's evolution into Hawkgirl, introduce Hawkman and explain their origin story while battling it out with the new big bad, Vandal Savage. It was too much to ask from the already crowded storylines and ended up feeling like an exercise in synchronicity, with producers planting more seeds than they could reap. The crossover event was no longer a fun way to contrast the two shows; it now had to serve the much larger purpose of setting up an entirely new world. With so many different balls to juggle they ended up turning both into an Indiana Jones knockoff, filled with plot contrivances needed to push the Legends characters into place.

Legends of Tomorrow has required far more from its sister shows than anything we've seen before. Of course, you cannot hope to compare the origins of The Flash to the development of Legends. The former only required the introduction of Allen to Team Arrow before he was ready to build his own team, whereas the latter needed investment in many different heroes, criminals, and bad guys alike. However, it is clear that asking two shows to set up nine different main characters while still progressing their own storylines is a lot to ask.

That being said, both shows managed to pull off this herculean task, albeit with a few missteps. Legends of Tomorrow looks to be another big hit for the network, and now that the shows are done ushering in a new spinoff they can get back to focusing on the things the excel in. This return to form is something we've already seen in The Flash's return as they focus on Zoom, the multiverse and having a bit of fun. Arrow is likewise primed for a strong second half as they deliver on a number of plots hinted to throughout the season. We'll have to wait and see how Legends distinguishes itself in this ever growing playground of superheroes but with the talent involved - and the sacrifice that went into the set-up - it should be a fun, compelling new addition.

The Flash airs Tuesdays @8pm on The CW. Arrow airs Wednesdays @8pm on The CW. DC’s Legends of Tomorrow premieres on The CW on Thursday, January 21, 2016.