Hi. As you see this guide is about newest LoL champion - Vi .
I can say that's my first guide too. Lets see, what can we say about her:
Quite good base damage, unfortunately few health. Not so squishy, but only when well built: she isn't typical offtank like , - they need some ad and some health and beat everyone on it's lane. She's rather simillar to , but not really - why? Both built in atk speed + tanky items = insane. But still is different, maybe better, maybe not. One of things which make Vi better than Ire is her very elastic q ability valut breaker - it means she can break away even through the thickest walls. Also, by the , , - easy chasing the opponent, and skill interrupting ( , )

Why did I buy her?
I'm kinda bored of these "hellish-op" solo toppers like , , ... I want check someone who needs more expirience and is more difficult. Not only jump+q, jump+q. And she looks great, so steampunky<3

Pros

* Great escape and chasing mechanism
* High base damage
* Durable
* Many knocks
* Blast Shield based on max health gives you quite preponderance at earl game

Cons

* Mana hungry if you spam e for farm
* Few base health (and she needs a lot)
* Weak untill lvl 6-8 (I don't suggest 1v1 fights at top against volibear, malphite, darius and many others)
* Very hard to play against ranged champs ( Gangplank, or Pantheon)

Here we can discuss whole day and night. My suggestion - expensive but durable - helps having you as much "luck" as possible. Ppl say "lucker, lucker" when you kill 'em with 30 hp left. Another thing is more health - more shield. You can built her in full health like warmogs or another items, but don't forget that health isn't everyting. As I said in introduction she must have attack speed to make her w effective, and damage.
Ofc, you can use armor seals and ad quintesences, but then you can have little less "luck". Runes and masteries give together about 13% health more. In earl game it's like 70-100 health, but later it can be even 300 or 400. It's not so few at all.

I already read many guides which ppl make about her build. Everywhere I saw brutalizer, and in my guide - there aint. Why? I prefer her tanky - I take less kills but more assists. Adc must take kills only. So this is why I take def masteries instead of offence. If I play def - I don't rly need this item, I have armor pene in last 9 points spent in offence, and much more needed item is phage and frozen. You must get it as fast as possible - as I said she has great chasing mechanism - your target practically can't runaway. It's because of slow in frozen, and furor in boots - in easiest way you need only to spam aa and kill is free.
Why do I sart from doran?
Health, ad, vamp. Simple. You aren't jungler so you don't need boots at the begin. You play def so you don't have to runaway. You have much health so you can buy pots later. Better last hitting.
In last match I bought dagger after boots. It was quite fantastic. And I suggest buy it before phage.
Tabies or mercuries? Situationally. Personally I prefer mercuries - mr, tenacity. It's important against jax, singed.
and - most op items for her. With these you're practically undefeatable. But it's not everything. Just farm up for zephyr and iceborn's. Watch the powah =) Attack speed + many slows help you easy get the survivors after dragon/baron ganks or teamfights. You won't (at least you shouldn't) be focused so it's your job.
Two last items slots: for true late game. Now you can buy what only you need - more ad, more def, guardian, everything. I chose warmogs and mercurian scimitar situationally, mr, smth like cleanse, health. Another choice is warmog and atma, but core - I think - is warmog.

Guide still in remakes - I need observations and expirience with her to write total, well built guide.