Believe me i play sivir when i get the chance.. most games im tanking or they need AP.. Ur build is terrible... yea you have lifesteal and AS.. o goody now wat if you get stunned by taric or panth??? 2 secs later ur dead and ur Life steal does **** for you..

I'm afraid this build is rather poor - you stack far too much lifesteal and waste crit chance. You have little in the sense of auras and you cannot afford anything due to the zero mana from runes and items. You have no armor pen, etc, the build just doesnt work im afraid.

If you are not using Sivir's Ricochet in a team fight, that is simply a huge waste. You can be attacking their entire team at once. And also, if their team actually builds armor and/or thornmail, your basic attack is considerably weakened and due to them stacking armor, the magic damage from Boomerang blade is awesome. And ricochet is not a spell you use when it is up, it is a passive.

Thats why you should not use ricochet and boomerang evrytime it is up! Thats the whole point of this biuld. To make you reallize that sivirs auto attack is EPIC and abilitys isnt always needed.

Spell Shield gives 50 mana, which is not a whole lot when you are using boomerang blade every time it is up and when you have ricochets bouncing all around draining mana quickly. Especially with increased attack speed you will lose mana even faster and halfway through a fight you will suddenly find that you no longer have any mana and you are dead. Btw I am reporting you for rage-voting down my build in response to me voting yours down for good reason.

I looked through your sivir biuld and it was good but i its too much mana you dont need it. i'm guessing your good with sivir and take my advice and try out this biuld or ateat dont buy as much mana and you will see that it is unnecessary because Spell Shield gives so much mana

For many different reasons, this build is very very bad. As you can see through looking at my Sivir build, I also promote the multiple Bloodthirster path, but you have to have more survivability and more mana than your build provides.
1)Sivir is an awesome mid if played correctly and often this means through the use of Ricochet. I always focus boomerang blade with one point into spell shield and then ricochet whenever I cannot choose boomerang blade. For a ranged champion, Sivir has a significantly low range. However, through ricochet you can still hit the enemy mid-lane champion without getting close enough for them to hit you and through rushing a Manamune, you will have no mana problems doing this.
2)"It dose not give more mana when disabeling an incoming ability." I'm not exactly sure what you are trying to say here because of the poor grammar, but spell shield definitely allows to to receive back more mana after blocking an incoming ability than it costs to activate.
3)Please fix the grammar and spelling throughout your build so that you are at least saying what you mean to say.

Acctully what you are saying is very wrong, try it before saying it sucks. Manamune is a wast of time and money. If you know how to use Spell Shield you take almost no damage since the life steal stacks with ricochet. You will be imortal. If you try the acctual biuld in game and get the whole biuld dont and still think it sucks then you can tell me. And i might change my mind. But I use this biuld almost everytime i go with sivir and i always end up with good score. Even though i have bad in start when i got some items i can take on anyone.

This build is horrible.. other than the mass Lifesteal you have no other form of survivability.. if you are even saying becareful of ur mana then y not grab a manamune then a bloodthirster??? You also have no way of slowing down an enemy so they can easily escape u.. Frozen Mallet grants health, AD, and a slow.. overall i say terrible build