I agree with above too and I dont get the ABILITY SEQUENCE.
There is no logical system in for me. Not maxing one spell first?

I agree with above, and some things I'd like to add:

You have BB Coding, but still walls of text (Early game, Mid game, and Late game)
Consider adding farming to late game, mid game, or late game, and add unique skills to skill sequence, because both chapters are really short and better put with another chapter.

Ok, I'm not gonna vote but you have a lot of misconceptions and bad options on your guide, and I'm not even talking about Vi alone:

• Starting item: You don't have to start cloth. Crystalline Flask + pots/wards will give you a lot of sustain, spare you pot gold when you recall and actually give you jungle vision for a while;
• You have nearly no damage before your 4th item. Seriously, Black Cleaver works good with Vi's kit, if you want tanky then Frozen Mallet will serve you greatly too, spares the need for Iceborn + Warmogs;
• 22/8 Masteries makes no sense. You either go 21/9 and get that Veteran's Scars (I mean, you got Frenzy when you build 0 Crit Chance? And no, you don't need crit on Vi) or the typical 9/21;
• Your english needs a lot of work. You should get an English-knowledgeable friend to help you write guides;

You have some good explanations and your runes are correct.