Honestly, all of these'recomended builds' seem pretty meh to me, she needs different things at different parts of the game, i've seen so many bad VI's build like what you guys recommend and become **** lategame, or rush phage, and honestly it sucks.
I've played her for almost 2 solid days on pbe, i can say without a doubt
Is one of the best builds for her
It gives her EVERYTHING she needs
Boots are up to personal choice, situation though.
Her never ending slow to stick to enemies and punch them
Attackspeed for more punching
Tanky to survive while punching
Pen to make her punches hurt even tanks.
She needs so much damage to stay good lategame, she also needs lots of tankyness, this build gives her EVERYTHING she needs.
I know iceborn gauntlet isn't the best thing for her at first, but think of it, armor, cdr mana, and everyone of her E's and Q's gain the proc, on top of a 100% aoe slow that you don't gamble on the proc, she's very easy to kite when her Q is down, this helps her stick with people a lot easier, it's worth the tiny bit of ap you pay for that's not really used.
BT instead of black cleaver, if you want i guess? she already gets over 300 damage with this build, she could use life steal i guess but that's completely up to you, the cdr from bc seems to be more valuable to me.
50 more attack damage and some life steal vs all that delicious pen and cr, hp. your call.
Her whole kit plays off of killing things with her abilities and a couple autos, she's much more reliant on her abilities than auto attacks so life steal midcombat feels useless
I feel the pen and cdr to work better for her, if you're careful in lane 2 dorans blades her shield and a couple potions are all you need to keep her healthy through laning phase.