In a recent interview, John Boyega opened up about Finn's character arc in the Star Wars Sequel Trilogy and how he expected his and Rey's story to play out.

Anakin Skywalker, meanwhile, was trained by Obi-Wan in the hopes of bringing balance to the Force. However, after aligning himself with the dark side, Anakin went against his master to become Darth Vader. Finn's Force-sensitivity, coupled with his past ties to the First Order, could well have seen him go against Rey in the same way.

I think I assumed he was Force-sensitive from The Force Awakens script or at least by the time I got to the end of The Force Awakens script. I thought they were planning dual Jedis. I actually thought that they would Obi-Wan and Darth Vader us a bit.

Finn is introduced as a character with a fresh perspective on the usual good-versus-evil events of the Star Wars films, being a former Imperial Stormtrooper. But beyond a rivalry with his former commander Captain Phasma (a plot thread that is swiftly wrapped up in The Last Jedi), this is largely left unexplored.

The Star Wars sequel trilogy could have taken a far more dramatic turn than what we got, at least in John Boyega ’s mind. The actor recently revealed that after reading the Star Wars: Episode VII – The Force Awakens script,

John Boyega has previously described how disappointed he was with Finn's arc in the Star Wars sequel trilogy. Now, Boyega has spoken about where he expected Finn's storyline to go in the sequels. Appearing at Fan Expo Boston,

John Boyega had to deal not only with intense vitriol from racist fans outside the franchise, but also feeling devalued within it. In the past, he’s spoken about how the experience changed his perspective on the industry.