Hey, (scuse my english, maybe you speak french ^^) I am a riven's main player too, i play in West Europe, and i'm 23 (soon 24)

i just discovered your build and tried it and approve it :D

i have a few questions because you use items i have never seen used before in guide ^^

i wonder if you use the same build in 5V5, taking BT instead of sanguine blade and start with doran blade and a potion ? ^^
usually my build is doran => 4 long sword => bruta => vampiric scepter => last whisper => BT => Ionian's boots => ravenous hydra => 2nd BT => bruta sold and spirit visage

- why choose berserker's greaves instead of Ionian ? does the attack speed so important you throw away 15% CDR ?

- I took Last whisper and sold brutalizer, but now realize that black cleaver is more efficient, if you can touch 5 times your opponent, and that is why i prefer last whisper, from the first hit you deal as much damages as you can deal ^^ but now i'm not so sure about that ...

- Thanks to you i took the 3V3 equivalent of infinity edge, i now know how terrible it is on Riri, i thought a long time of it but was always taking a second BT instead (the passive works with each BT), but 1 369 in one strike ... wow ...

- I privilege damages over armor, do you think the same way because of the efficient of a well used shield ? if you're late in the game, do you sacrifice damages for armor or mr (you have Spirit visage but do you take malmortius ? ) or do you trust again in the shield ?

- many people think Garen isn't a riven's counter, but i can tell he's a pain ;) but i think Renekton is very very very less easier to deal with than Garen ^^

I'm glad to have found your guide because he's really great (a bit too short :'( ), and i hope you'll make others for top, mid and Jungle ;)

its on its way soon

Looking good. +1
What about a jungler build?