The Doran's Shield is in my opinion the best choice of a start on vi the health regen and the health is really effective and the health are giving you extra on your Blast Shield that u get 10% of max health when using an active ability.

If you're facing a tank enemy you want to get a fast The Brutalizer for the armor pen and the cooldown reduction is aswell a great stat for vi's kit. After that you want to get trinity force and starting with the phage then sheen but if you are facing a magic dealing top laner like Zac Shyvana you might want to get Hexdrinker before starting on the Trinity Force.The rest of the item is pretty free to buy depends on what your team need but i suggest to not build much more offensive items then Black Cleaver Trinity Force Maw of Malmortius and then add some defensive items that's good if u meet Ad/Ap heavy teams. And Mercury's Treads boots are very effective becuce as a bruiser you cant afford to be CC'd to long.

You will need the offensive items first in the game becuse Vi midgame is sick becuse u can chain CC on you own untill your target dies and you wont really need an defensive item untill the enemie adc and midlaner gets their Zhonya's Hourglass Guardian Angel that will interupt your CC and u will be vulnerable for counterattacks when u will be in need for Randuin's Omen or Guardian Angel

When u are facing a tank you should focus alot on trading when u have your passive Blast Shield up and when u start with your Relentless Force you have 2 charges so u can auto attack then reset the basic attack timer by using Relentless Force then auto attack and Relentless Force again for maximum damage and you will win the trade 99% of the times becuse u get your shield. Stay aggressive and at level 3 u can constantly bully you opponent with Vault Breaker Basic attack Relentless Force basic attack Relentless Force that will deal about 300-400 damage depending on enemy's defensive stats.

The most important thing about playing Vi is that u always want to get an auto attack between all your abilities so u can proc Denting Blows as often as possible this will make an huge impact on your damage.

at level 6 you can easy dive someone alone or with your jungler i recommend to start the dive with Vault Breaker if possible Into the regular combo Vault Breaker Auto Attack Relentless Force Auto Attack Relentless Force and now add ultimate to this and the Final rotation will be following.



Vault Breaker , Auto Attack , Relentless Force , Auto Attack , Relentless Force , Auto Attack , Cease and Desist , Auto Attack , Relentless Force.

And that should be an all in against any champion and they are CC'd about the whole time and with the runes and masteries i have used you should have a third Relentless Force up about right after your ultimate is used and Vault Breaker should also be up just after your third Relentless Force

Vi is a great champion in team fights she can easy lock down the highest damage threat with just her ultimate and then switch focus with your Vault Breaker to get into the next biggest threat or help your carry's. But as you know if the target you ultimate jumps away you will follow them all the way so it can be very dangerous if you get over a wall and your team cant follow up then and you can get into an easy kill for your enemy's.

As Vi you should engade freely becuse with the damage you get from the build i have shown you, you can easy kill an ADC/AP Carry easy by your self and if you wanna engade by suprise you can Load up your Vault Breaker Then flash while loading then using Vault Breaker and u will suprise them everytime and pick up an easy kill if your team are ready.

You can also in teamfights save your ultimate if you can engade with your Vault Breaker so when the target gets into a better position with flash or something else u can just ultimate and you are right back on them to be as annoying as possible and stick to your target becuse no one can defend you against Vi's ultimate

Pros

Shes a great initiater
She can burst anyone with her rotation
She is fun to play
can be heavy tank or used as an assassin
can move through walls with 2 abilities
can easy set up ganks by her self
you can use flash while charging Vault Breaker

Cons


facing a enemy with a gap closer makes it hard to engage with Vault Breaker
She is pretty much all in if you use Cease and Desist you will get into the middle of their entire team
if you use Cease and Desist a bad moment you can end up alone in the middle of the enemy team
she requiers alot of skill and clever targeting