I absolutely love Sivir she is my favorite champ so believe me when i tell you Rito
You cannot repeat CANNOT keep her crits on W the way they are they are definitely going to have to be reduced crits otherwise you will have Sivirs one shotting entire waves with a single W auto attack and doing 500-600 damage per bounce on Ricochet.
I just tested it (In a bot game) and once i got a few items on me a single attack from W was enough to clear an entire wave of minions and a Single W with all 3 attacks at 100 percent crit chance wiped out 3 enemy champs by themselves
and i made sure to sit AFK until the bots caught up with me.
Again i absolutely love Sivir to death but this W with the way it currently is (I know its PBE for testing) Will be so overpowered that she will be instant pick or ban guaranteed.
EDIT: I don't know why i am being Downvoted here but if someone could explain why they downvote that would be nice.
I am pretty sure that alot of you aren't going to be happy when those Ricochet bounces hit you for 500-600 damage when you are in the backline.
EDIT2: Wow people see 100 percent and automatically assume i am going to try and build 100 percent crit chance every game. No an average game will with an essence reaver crit build will see an ADC with at least 70 percent Crit chance which is more than reasonable for any build.
Stop looking at the 100 and then going hog wild jesus.
,
and an attack speed based crit item
Or
Or
.