Hmm this is a very scrambled build. i for one hate boots of mobility - keep it for an assassin character - also spell vamp isnt brilliant for sivir as her only spell is boomerang. which doesnt give you fast enough health return to warrant vamp. try her as a hybrid, using AD/AP together. I like items such as Guinsoo's in there.

**** build

It seems to my humble person that you don't really understand a lot of what Sivir is about. You should try getting some variance in your items and runes. Try getting yourself some armor, MP regen for your ricochet, dodge to stack with your passive, and other itmes except for AP and Magic Pen. For your runes I like your seals for AP, but maybe try out some dodge, MP regen, and perhaps a crit for your others. One more thing: Try to write your build coferently; it was horribly difficult to read to your build. -1

Very nice build lol, i went 18/6/9 at the first time