“Why didn’t we think of it sooner?” It wasn't until 3 years later that Eric Kripke came up with the idea to introduce a game-changing Star Wars-inspired twist to Supernatural
Supernatural's creators didn't come up with an obvious game-changing twist until 3 years later, enriching the TV series' world.
From the beginning, Supernatural was the story of two brothers who were trained from an early age to fight demons. And they began their epic journey the moment their father disappeared. That's when they were embroiled in their greatest battle, facing the worst demons known to mankind.
And although demons were part of the plan of Supernatural's creators from the beginning, at some point they realized that the Winchesters could not be their only opponents. The human brothers against the unearthly beasts alone wouldn't stand a chance, so after 3 years the idea of introducing angels, whose appearance seemed the natural course of events, was born. The creators themselves were surprised that they hadn't come up with the use of angels in their story before, as Eric Kripke confessed during an interview with the Chicago Tribune (via The Winchester Family Business).
We always had the demon plan [for the seasons as they progressed], but the angels came in, and it was one of those things where it’s like, if anything, we felt stupid for not thinking of it sooner – because how do you have demons without angels?
Suddenly, when you bring in the other army, now you have these two massive armies of demons and angels — they can mesh and clash in a way that’s really satisfying, and [you can have the giant clashes] just off camera.
The introduction of angels to Supernatural definitely enriched the story, the center of which could now be the coming apocalypse. In addition, by adding them to the TV series, the production gained interesting characters, most notably Castiel, who was only supposed to appear for a while, but stayed until the very end, becoming one of the most likable characters.
The inspiration for introducing a second significant “faction” may have come from the Star Wars series, to which Kripke at one point compared Supernatural. He mentioned that the angels and demons in his TV show are like the Empire and the Rebels in SW.
We slap our forehead against our hands, and say, “Why didn’t we think of it sooner?” Like, look at “Star Wars” for a moment. You have this massive empire and you have this massive rebellion. And they were having these massive battles over countless planets. But the story is about one farm boy, a princess and a pirate.
In this way, Supernatural had its two powerful players, among whom alliances could change, and people were somewhere in the middle of this dangerous battle. Fans, on the other hand, could follow these events with commitment, rooting for one side.