Ooooh, excellent? An Ado Edem Bad End? AWESOME.
Also, with regards to the alternate playable Shirous:
Fate!Shirou and Saber's combo attack = Traced Caliburn Slash, like in the famous scene. Simple, but effective - and powerful.
UBW!Shirou and Rin's combo attack = based on this, with swordspamming, gem-magic blitzkrieg and Rho Aias being used with the finisher:
Makes the Love Love Fist Projection look like a bitchslap.
Also, this game needs MOAR SRW references.