The animation looks fine. It just needs to be faster, and with smoke poofs and Shadow Blades looking purple particles trailing off your weapons as you fall on them.
The damage has to warrent its use on-CD, too.
The shadow clone could do with some work too--Maybe floating behind the target or you while it's 'observing' you; then mimicing your abilities, then when it's done disapearing in a Vanish poof.
People forget that particle effects do a LOT for WoW animations. Without them, almost every ability would look incredibly stupid.
Also, I don't understand the people who actually like the horrible FoK animation. I liked it when they were actually little 3d daggers that flew out from you, rather than weird purpley energy with literally flat wall-tacks flying out.