The Hill of Swords/Awesome

"Shirou:"
 * Numerous Moment of Awesome, but the one that is a cut above the rest is the Battle of Saxe-Gotha.
 * Shirou beats the crap out of Guiche so thoroughly that he comes back to learn how to do that.
 * The entirety of Shirou vs Karin. Starting with Shirou surviving the equivalent of octagon class magic (which manages to break Rho Aias), then ending with the most badass Crane Wing Three Realm this Troper has ever seen in written form.
 * This troper is pretty sure it should be called pentagon class magic (since in The Familiar of Zero each class of magic is twice as strong as the previous one), but that doesn't make it any less awesome.
 * A more subtle one, not related to combat. When Louise finally drags a confession out of Shirou that Yes, he wants to save Tabitha, Shirou proceeds to pretty much single-handedly create a Black Ops program for Tristain, all in order to do so. The Smart Guy of the Undine Knights is thoroughly amazed by Shirou's ingenuity.
 * Throughout the entire story, Sheffield, a Servant bearing the Mind of God class, has been progressively built as the biggest threat to Shirou personally. Each time they clash, the battle scenes grow progressively more and more awesome until Chapter 22 wherein Sheffield realizes just how powerful Shirou is. According to the author's notes, this single scene had been planned from the very beginning of the fic, some 300,000 words back.


 * And even with the above spoiler,
 * Even better, after all of the impressive magic and tactics thrown around,