Why Fate/Zero Works As A Prequel

On the whole, most will make the claim that prequels don't work, fundamentally. They don't work because anyone familiar with the original story already knows the fates of any characters from the original story, and because of that, there's no real tension or suspense. Moreover, they already know how story events will play out, because they already know where things are come the time of the original story. Anakin Skywalker was always going to become Darth Vader, the Galactic Empire was always going to take over the galaxy.

Why Fate/Zero Works As A Prequel
Source: Pinay Diaries PH