Hey guys ,ive just started learning riven and im using this build :D ,
Ive read many guides and watched alot of videos ,most people seam to go 
after this but ive also seen
after last whisper/ghost blade then 
and lastly 
What do you suggest on this build ? last whisper or ghost blade,im thinking of going straight into black cleaver after hydra because then i get the much needed cdr What do you riven mains use ? any advice would be nice (:
I don't main Riven but i already know a lot about her. key here is to acheive 40% cdr. Boots and a brut will do that. Last whisperer is needed for sure. And tbh, it all depends on your match up. Sometimes you will build a 
.
Her usual build will be this (Only build BC against heavy ad) and a situational item. that could be for heavy ap damage, for more LS, 
for the lulz, 
for over all def and the passive, and perhaps if ad is getting out of control, then you could go for this as well : 
.
http://champion.gg/champion/Riven
Look at this website and this could help you a bit.
First of all, dont play riven lol
Second of all, I usually build BC or hydra first (depends - hydra if im ahead, bc if im behind), then the other, then youmuus, then LW, then BT or defensive item (GA). Boots t1 should be at the beginning then get t2 after first item
