Back in the mid-to-late 2000s, Konami had plans to release two different Castlevania movies. One was going to be a live-action film written by Paul W.S. Anderson and directed by James Wan, and the other an animated feature written by Warren Ellis. Both of them ended up getting cancelled.
While the animated movie ended up getting a second chance as Netflix's Castlevania series, its live-action counterpart was not so lucky. Even before it was scrapped, Anderson was removed as the writer and replaced with Sylvain White, for reasons that I am personally unsure of.
Fortunately, we still have at least some idea of what the movie would have been like. The entirety of Anderson's script was leaked onto the internet at some point, as well as a fragment of White's script. It seems that White had been tasked with rewriting the movie from scratch, as the two scripts are vastly different. Anderson's story would have starred Simon Belmont, while White's version focused on Trevor. Not all of Anderson's ideas were completely thrown out though, as both scripts feature Christopher Belmont as a supporting character, and have a character named Akbar as a companion to the Belmonts (Though in Anderson's version he's largely referred to as Vlas).
The Paul W.S. Anderson Script
The Sylvain White Script