The best item set is boots, three pots, brutalizer or dorans blades depending on how well you do your lane, phage into frozen mallet, lifesteal scetper into bloodthirster, atmas or FoN or QSS depending on the enemy team's damage, and then you can build a second BT or more survivability, I liked having a GA on her or possibly a frozen heart for the extra cooldown reduction.

hmm... PD doesnt interest me much but starks could be useful with his ATS-Lifesteal aura and also the -20 armor aura. Ill give it a try.

I would consider attk speed as well since she is pure AD like PD or Starks, i personaly think stark would be more benifical then hextech but thats just my 2 cents

These designers also give us completely broken and useless item builds;p

yeh she lacks some base HP. also her armor levels low. so a supporter in your team would be great to get off the squishyness.

spellvamp doesnt have anything to do with magic dmg. skills with physical dmg also proc Spell Vamp.
so yeh it gives unneeded AP, but who cares. It gives 60AD, 20% Lifesteal (more than bloodthirster with less than 20 kills) and 25% Spellvamp. Also the active is nice to chase those bit**es who try to escape.
Ki Burst is good.. but only stuns 0,5 secs so the slow really helps. also 300DMG on activation.

I tried this today. like it a lot better than the default rec build.

Why hexetch gunblade does riven do any magical attack ?

Personally, I can't see how Hextech Gunblade is helpful at all. None of her abilities scale with AP and none of her abilities deal magic damage so spell vamp is useless. The active would be nice but it isn't worth the wasted stats of gunblade.

love it great build, still a bit squishy though

Love the guide, and with a little variation in my own personal build, that being after Youmouu's getting the first half of gunblade, the lifesteal cutlass, then Warmog, then Atma's, and I absolutely wrecked face. Love how you include early brutalizer and gunblade, as they really work great for a lot of AD casters, despite the peoples initial reaction, "Wtf y u get ap?" It really helps a ton, so long as you USE the damn item actives, its perfect. Will +1 when I can, so long as I remember, heres to hoping I do, and have fun with Riven!
Also, might want to edit the parts of your guide involving sheen, it really doesn't work on her, and a suggestion from me. For Riven I much prefer starting with boots + pots over the dorans shield, as with the runes you really dont need the extra tankiness and the boots pots lets you play a lot more aggressively and lets you get away with a lot more early.

err she doesnt do magic damage, dont get hextech gunblade, get a doran's blade or boots or cloth armor/5 pots depending on your lane and then go brutalizer after level one boots, then build bloodthirster or wriggles