This riven agressive build is realy good cause:
-She can slow targets with Frozen Mallet.
-She has got the bonus damage when she recieves attack damage. Thats only defensive part, ok? Now you will see the insane damage that she can tank in few seconds,
-Bloodthirsters Give you the best survivality ever.
-Madrez Bloodrazor are realy good cause they give AD and also Speed with bonus of Magic in Attacks, also the armor counts for suviving

We use those desolation Marks and Quints, well to penetrate lot of armor from your enemies and then deal massive damage.

The other runes count on deffensive part that you ll reduce the physical damage and the magic damage from enemies attcks that grants you a 20% less damage fron magic and also physical damage, combined with the thornail they work great toghether. Full build has like 70% reduced physical damage

Ok, those are common masteries like AD carry use, and part of tank that will give you not much but part of your resistance :D

I ussualy use Flash and Ignite for the early game, but you can change them for the ones you like.

You could also use ghost to run away but, I prefer flash, is up to you.

I dont reccomend to use Heal, I think you have enough life steal to heal with minions or beasts.

So what we want to do is lead a GANK starting with broken wings. Be quick stun them and chose the main AD carry and kill him first, use 1st time broken wings and hit, 2nd time and you hit again then last time, and you keep on hitin if someone is escaping use flash or valor and stun him, he him kill first and then choose other target, i recomend the AP now cause you flashed near them to chase your first target, it should be easy to kill them one by one froam behind.

You should almost always lead the gank