Some people have already tried to do this, the most notable one being Fate/oracle on Spacebattles, but even that one is still only at the Fate route, and it doesn't even include a reaction to Fate/ Zero's events. If you want you can do a summarization of Fate/ Zero and have them react to that, but don't exclude it entirely. I do want them to react to the entirety of Fate/ Zero if possible, though. Other than that, I also want them to react to all three of the Fate/ Stay Night visual novel routes, in order from Fate to Heaven's Feel. Just like Fate/ oracle, I want the bad ends included as well. As for the characters I want reacting, have all of the Fate/ Zero masters and servants and all of the Fate/ Stay Night masters and servants. Of course, there are other characters that need to be included too, such as Maiya, Irisviel, Natalia, and anyone related to Kiritsugu's past that you deem relevant enough to contribute to the reaction. Maybe even add Waver's "grandparents" too if you so wish. These examples are all from Fate/ Zero, as I can't think of many outside of Taiga for Fate/ Stay Night. You also need to include True Assassin to the list of reactors, and have the reactors from Fate/ Stay Night all be from post UBW, rather than prior. This is just a matter of personal preference, so you can also have them be pre- Fate/Stay Night too if you want, though I'd prefer the first option. Definitely have the Fate/ Zero reactors be pre-canon, though. It doesn't make much sense to do otherwise, in it's case.