I've been messing around with Vi on the PBE. Anyone else trying out any builds?
She seems pretty versatile, in that you can build her Tanky DPS/armor shred, AS/%HpShred, or even as a Tanky Disruptor. And all three felt pretty good. And more importantly, now that armor is being shredded like crazy and more people are building raw health, she can very reliably transition into either an armor pen build, or an hp shred build.
She definitely wants Trinity Force. She wants Sheen, she wants Phage, she wants Zeal. That basically starts all the builds. After that, you can get up a Brutalizer, and head into Black Cleaver. And she is someone who could even build Ghostblade. She would also need some defenses naturally. This build would look something like:
Another route would take Ionian boots, and head towards Zephyr. Her one problem is that people sort of run away from her, so the movement speed on Zephyr, along with the Trinity Force slow proc/movement speed seems nice. All that attack speed synergizes really well with Blade of the Ruined King. As her W is chunking % health, so is the BotRK.
Blade of the Ruined King
Finally you can even build her as a tanky disruptor. Like I said, she definitely wants Phage and Sheen, but that doesn't ALWAYS mean Trinity Force. The combo of Frozen Mallet and Iceborn Gauntlet makes her stupidly disruptive. Since you have so little damage here, an offensive MR item can be used.
Maw of Malmortius/Mercurial Scimitar