So this is my first guide. I know, how cliche, every guide says that now a days, huh? anyways, I spent some time reading through the guides and playing Sivir, and I wondered.... What if you maxed Spell Shield first? I found nothing on the subject, and eventually decided to make my own guide about it since I really enjoy the results of getting shield spam early game where it can save my life in lane more often then in team fights with focus fire and CC spam. The result? more sustainability early game, better farm, and very difficult to gank except for some extreme situations.

I decided to go with Marks of Desolation, Seals of Clarity, Glyphs of Focus, and Quints of Desolation.

Armor pen is pretty obvious since I'm pretty much ignoring BB till end game, I'm focusing solely on her AD for my damage.

Her regen doesn't really need to be worried about till late game when I'm starting to use BB more often, which is why I went with MP5/level, giving her a better bonus late game for her mana regen.

Shorter cooldown on shieldspam and on the hunt is valuable, and getting CDR in game costs a lot on the damage portion.

For my masteries, I focused on offense rather then utility. More damage, attackspeed, crit, and some cdr. More farm means a better sivir. I avoided Archaic Knowledge since I don't use BB that much.

Then, of course, I grabbed the dodge specialization to synergize with Sivir's passive. Got to keep moving.

21/9/0

So far I've only gone with AD, AS, and Crit. I not sure what else to try with this build, and I don't even know where to start with Aura Sivir, so I'll save that for another time.

I start out with boots and some hp potions. After I have enough for a zeal and a vampiric scepter, I usually recall, and look for any potential ganks. With three potions and spell shield, I can stay in lane for a long time. To avoid getting ganked, this would be a good time to get a ward for the river bush. Every time you go back you should make sure you're warded, to avoid any unpleasant surprises. This is assuming you're in side lane. If you're mid, you should probably try to get more then one ward if you can afford it. Keep an eye on your side lanes, and play defensively.

I try to finish my first bloodthirster before phantom dancer so I can start farming that damage. Again bloodthirster before Phantom dancer, and then finish off with an infinity edge for extra damage and crit. Your movement speed should be around 499 at this point, and you should be critting every shot, with an attqack speed of 1.8ish without on the hunt. Pushing a tower should be no sweat with a minion wave, or even without at that point.

Spell shield RULES. Reducing it's cooldown first is my top priority, and the entire concept behind this build. basically, I took a look and Boomerang Blade, and saw that it took a quarter of my mana every time I used it, till around level 9 ish, and that made it difficult to keep Ricochet up a lot early game. I wondered what if I didn't use boomerang blade at all. And switching it's priority to Spell Shield not only solved the problem, it made it possible to keep Ricochet up all the time without having to worry about my mana.

Once the other team realizes how I can harass them from the other side of their minions, they'll want to try to stop that, and slow down my farm. They may not want to feed my spell shield, or even get near me, but they know that letting me farm without harassing me will be even worse for them in the long run.

So max out Spell shield by level 9, and level ricochet and on the hunt respectively till level 12.

I start leveling Boomerang Blade last because it really starts to shine once you have some Attack Damage farmed up with your bloodthirsters. This really makes farming minions waves and pushing towers with teleport a breeze. One BB and a couple of hits with ricochet will devour a minion wave.

Ghost works so well with her ultimate, although some people might think it's useless because they already have a speed boost. Sometimes it's not enough by itself. Flash could be a suitable replacement, considering you can combo it with your ulti as well as most people combo Ghost and Flash together. Teleport is a must for Sivir. Being able to port in and finish off a tower with a minion wave while the team is engaged, or even hop in to defend a tower, crushing that enemy minion wave before the enemy team gets two hits in.

Pros-
Great Farm
Able to stay in lain very long
Harass from a long distance
good escape options
Block spells every few seconds
hard to harass her, have to commit or ignore

cons-
Squishy
being focused makes spellshield ineffective