This item is like LW, but for ap champ. Required when they get MR, optional when they arent.
This item is build 4% of the time in ranked, as of lolking.net. Why so low? Considering that 2/10 are ap mid and that there is some games where they aint any ap, thats 20%, so that mean 1 build on 5 (ap mid) got voidstaff. And void staff is a late game item, so there is games of 20 ,imute when u dont have time to buy it. That would leave 1/3 of ap mid build wich would buy void staff. You cant say void staff isnt use.