Hi, I'm nrj6490 and this is my guide to Sivir. Sivir is an AD Carry who is primarily based around team utility due to her ultimate, On The Hunt, while also supplying damage through her attack speed, critical strike, and damage from Boomerang Blade. She can be seen as either an ability based mid game powerhouse (with a bit less power than the likes of Lucian, Quinn, or Miss Fortune) or a late game carry (although don't expect to single-handedly carry your team). Overall, she is an amazing ADC due to her utility as well as her considerable damage output.

Pros

+ An amazing team-based speed buff ultimate in On The Hunt that can be used to secure many a kill + Great poke and damage output with Boomerang Blade + Great tower pushing when Ricochet is active with the passive of On The Hunt + Ricochet and Boomerang Blade provide amazing waveclear + Spell Shield gives solid defense against ability based champions + Pretty strong at all points in the game + Good escapability

Cons

+ Doesn't outscale many late game based ADCs + Mana problems early + Coordination with team necessary to take full advantage of ult + Can be focused on easily if unprotected

Heal
Heal is standard on pretty much every ADC. The health in itself is useful for getting out of sticky situations without needing to burn the more useful Flash, and the speed boost can be the deciding factor in a chase. Be sure to share the heal with one of your allies by selecting them before casting.

Flash
Essential on most champions in the game, Flash has an insane amount of utility. Pretty simple. Flash over walls to run or go in, flash in or out of chases or fights, it pretty much depends upon your style. Be sure never to overcommit on a Flash, though, as it could go horribly wrong.

Exhaust
This is being taken more on ADCs now (with Heal on the support). While I prefer Heal, I can see this working on Sivir. It could be hard to close a gap without ulting due to her lack of CC, and Exhaust could fill that gap.

Ignite
Rarely taken on ADCs, this isn't that important on Sivir. If you're ultra aggressive, yes, Ignite could be useful in lane, but if that's the case, your support should be taking it.

Passive: Fleet of Foot
Gives a burst of movement speed when an autoattack or ability damages an enemy. Think Phage passive. This makes it very easy to kite or chase with Sivir, as you can outrun most enemy ADCs (without escape abilities of course) by autoing and landing Boomerang Blade.

Q: Boomerang Blade
A great main damage and poke ability. Be aware that it does cost a bit of mana (which you'll have trouble with early), but once you get Essence Reaver and Rapid Firecannon the mana refund should be enough to keep you rolling. You can just throw this into teamfights, but make sure you have a specific target in mind, so you can then go after them with auto attacks.

W: Ricochet
This is a great ability for pushing lane. Need to clear a wave? Just Ricochet into Boomerang Blade. Tower need to go down? Make sure there's no enemy champion under tower (to draw aggro due to Ricochet and go ham. Once you get points in On The Hunt, it also boosts attack speed while active, which is useful for objectives.

E: Spell Shield
Blocks next enemy ability to hit you. This is a great defense, either to eat poke in lane, or to absolutely reject an execute like Jinx or Caitlyn ults. It also provides good lane sustain, as it has no cost, and actually refunds mana upon successfully blocking an enemy ability. Blocks Dragon auto attacks as well.

R: On The Hunt
This is a team-wide movespeed buff, which is an amazing ultimate for two reasons: engage, and disengage. It's a stellar tool for positioning and flanking, which, if used to focus on the enemy carries, could win a fight. Of course, if the enemy team is low (or you are), it can be used as a chase/run tool.

Sivir builds like the new "AD Caster" sub-class (think Lucian, Miss Fortune, Quinn, Graves), but while her Boomerang Blade does have a high mana cost and does do a ton of damage, her auto-attacks are just as useful in chunking down enemies.

Essence Reaver
Core item on Sivir. Her need for mana sustain goes beyond the fairly high costs of Boomerang Blade and Ricochet, as On The Hunt, being such a useful ultimate, should never have to bow down to low mana. The CDR helps with your output as well (but be sure not to just spam Boomerang Blade before you get the chance to earn back some mana).

Berserker's Greaves
Although your recommended build (TY RITO) suggests that you take Ionian Boots of Lucidity, you'll already have 30% CDR after Essence Reaver and an AS/Crit item, which is pretty sufficient and fairly close to the cap, anyway. Berserker's Greaves help you clear and push down towers.

Boots of Swiftness
Only take if you really like roaming, but as stated in the items section, your abilities pretty much cover everything these give.

Phantom Dancer
This is probably the best choice for your customary Zeal upgrade. Due to the buff on her W (the ricochets can crit), you still have waveclear with your total 50% crit by this item, and you can duel way more easily.

rapid firecannon size-50 Rapid Firecannon
Take this if you feel a desire to boost your siege and poke game, in addition to your trusty Boomerang Blade.

Statikk Shiv
If you want even more waveclear/teamfight AoE

Runaan's Hurricane
Take if you want to be a waveclear machine. It also gives 15 on-hit AD, but you'll mostly be going for straight crit/speed/damage.

Infinity Edge
Pretty much essential on Sivir, and on most ADCs. It gives your crits the oomph they need with the 250% crit damage, and has a nice chunk of AD with 65.

Quicksilver Sash
Take this BEFORE Infinity Edge if and only if you feel that your Spell Shieldis too little to repel enemy CC (and if the enemy team has a LOT of CC). I do suggest getting it at some point in the match, be it now, after IE, or when building Mercurial Scimitar as your last item.

Lord Dominik's Regards
This should be taken more often than it's cousin, Mortal Reminder. Take ESPECIALLY if they have a lot of tanks. Even if their mid and/or ADC have more HP than you, the Giant Slayer passive will come into effect and give your damage against them a boost.

Mortal Reminder
Take this if the enemy team has either a lot of heal ( Soraka), lifesteal (dependent on some ADC builds), or a lot of health regen or return ( Garen/ Darius).

Maw of Malmortius
Around now, mages will start doing HEAVY damage. If you're worried about this, take Maw of Malmortius to live through teamfights and also to get some armor pen.

The Black Cleaver
This helps a lot with your kite and chase due to the Phage passive's synergy with your own. Also the armor reduction is useful in place of armor pen.

Duskblade of Draktharr
To be honest, not all that great on Sivir but it can be situationally good for locking up quick kills, which she doesn't necessarily excel at.

Mercurial Scimitar
Builds out of QSS, which is its most useful component, but it does have a LARGE chunk of AD (75, the same as Bloodthirster) and also some nice lifesteal.

The Bloodthirster
If you have a thirst for blood but never live to see it, this is for you. The shield from "overhealing" is very useful, and the 20% lifesteal passive gives SO MUCH SUSTAIN. On top of that, 75 AD.

Death's Dance
Gives some nice lifesteal, a ton of AD (75 again), and CDR to close out your cap. The most useful component is the bleed effect, which greatly increases survivability, giving you an opportunity to lifesteal some HP back before you die.

Sterak's Gage
Similar to Maw of Malmortius, take this if the enemy team has a ton of burst damage, so you can live through the burst and get 'em while their cooldowns are up.

Great Your ultimate and her Defiance (her ultimate'd E) synergize amazingly together and provide a lot of utility in teamfights, as well as with engage and disengage (if Karma takes Windspeaker's this will be even more potent). She also provides a lot of lane dominance with her poke from Q and the lockdown potential of W.

Great He can pick up CS that can fall through the gaps of Ricochet, and has long-range slow-poke, which makes it easier to land Boomerang Blade. If you whiffed Spell Shield, Unbreakable can protect you from punishment. Also, On The Hunt can get him into a great position for Glacial Fissure, which is an amazing engage.

Great Just... so much peel. Staggering Blow can help you land Boomerang Blade. Dredge Line can help you land Boomerang Blade. Riptide can help you land Boomerang Blade. Depth Charge can help you land Boomerang Blade!. With all that engage, combined with your chase from On The Hunt, many a kill await you.

Great Like Nautilus, SO MUCH PEEL. Zephyr and Howling Gale can let you land plenty of poke, and when you get a hankering to go aggressive, an Eye of the Storm on you plus maybe a Flash- Monsoon can give you plenty of leeway when trying to focus down the enemy ADC. Her ultimate is invaluable in teamfights, as well.

Good When she gets a stun, watch out. The Boomerang Blades land for days, and to make it better, Annie also does a bit of damage!. So just poke down and get off a stun, and you'll get a free kill.

Good His peel goes well with most ADCs, and On The Hunt makes it even easier to land it. Nuff said.

Good Morgana has a TON of in-lane poke thanks to Tormented Shadow, Dark Binding, and Thunderlord's Decree . Also, a Dark Binding is pretty much a guaranteed landing on Boomerang Blade. What's more, if they're already low and Morgana gets a Dark Binding and Soul Shackles combo, you can just ult up to get there and unleash your Ricochet and Boomerang Blade damage.

Good A landed Aqua Prison = free Boomerang Blade. Ebb and Flow helps sustain your health (so both health and mana are covered thanks to Spell Shield), and Tidal Wave is amazing on chases, combined with Fleet of Foot and On The Hunt.

Good Landing Death Sentence CAN make a great kill opportunity, but oftentimes it leaves you open to attack by the OTHER laner, or you simply can't follow up. Well, with Sivir, just Spell Shield the enemy counterattack CC, and use On The Hunt and The Box to allow for follow up.

Good If he lands the stun from Cosmic Binding, you can get off a great deal of damage. Caretaker's Shrine helps with sustain, Magical Journey gives Sivir some nice mobility, and Tempered Fate is a great ability when chasing, and, when landed correctly, can easily result in a double kill.

Good Tongue Lash makes it much easier to get damage down on targets, as you get a speed boost with Fleet of Foot while they get a slow. Devour can both help keep the enemy you're focusing in range as well as get yourself, with no defense other than Spell Shield and an ult with a long-ish cooldown, out of trouble. Also, be sure to use Devour in conjunction with On The Hunt to get off team fight-saving flanks.

Good Rocket Grab, Power Fist and Static Field is a helluva combo. It also allows you to land a great deal of damage before they try to disengage. Good luck to them. Also, with Blitz's Overdrive, you two can speed in and out of fights easily.

Good Three of her four abilities are stuns, which guarantee Boomerang Blade landing, and the other is a slow, which helps in chases when used alongside On The Hunt. Solar Flare is less useful in chases, but good for lane kills and teamfights (especially if you get a good flank with On The Hunt).

Good Since Sivir's defense is ability-based ( Spell Shield), she is very vulnerable to auto attack based champions like Vayne, Draven, and Twitch. That's where Shen comes in. Spirit's Refuge nullifies auto attacks, allowing you to win trades easily. Shadow Dash is great when chasing, and Stand United can save you when all your abilities are on cooldown and you think you have nowhere to go.

Good Her poke is insane, her root can help you get your damage off, and Inspire, or better yet, Inspire's Mantra bonus, when combined with On The Hunt provides SO MUCH MOVESPEED.

Ok Yes, he has a lot of poke and so does Sivir, so they should go well together, right? Wrong. Unless he gets the stun off from throwing two Time Bombs on top of each other, there's really little he can do in terms of CC. Sure, he can Time Warp the enemy, but that makes the follow up entirely dependent on you unless he uses Rewind, which then makes him unable to land the stun.

Ok Lulu doesn't necessarily go badly with Sivir, she just doesn't necessarily go well with her. Glitterlance and Boomerang Blade are both potent but easily juke-able forms of poke, and since Whimsy is Lulu's only CC besides the knock-up from Wild Growth and the slow from Glitterlance, being able to securely land Boomerang Blade becomes difficult. Also poor chase.

Ok Astral Infusion does help with lane sustain, but Soraka's lack of CC (disregarding the easy-to dodge Equinox) makes for a pretty boring lane unless you can land a lot of Boomerang Blades.

In the early game Sivir's biggest problem is mana. Boomerang Blade costs 70/80/90/100/110 per point, which means you need to be smart about mana usage. Look for abilities to use Spell Shield on to replenish some mana. Once you hit lv. 6, though, you may want to keep it up to defend against ability-based ultimates ( Nautilus' Depth Charge, Jinx's Super Mega Death Rocket!, Nami's Tidal Wave, and Ashe's Enchanted Crystal Arrow are a few examples). Despite the utility of Boomerang Blade early as poke, remember to take Ricochet first. If you see three or so minions all at low health and you don't think you'll have time for three autos, just Ricochet. Sivir can really use a level advantage to its potential, since with each level, Boomerang Blade grows stronger. If you think you have an opportunity to kill, be extremely stingy with On The Hunt, as if you burn it and are situated at the enemy tower, a gank would be all but inevitable. However, if your support lands a choice bit of CC and you want to follow up on the kill, feel free.

Sivir does pretty well mid game. Your Boomerang Blade is probably your best source of damage, but that doesn't mean you shouldn't follow up with auto-attacks, as crit can be just as useful. Anyway, the name of the game here is teamfights. Luckily, you have On The Hunt. This can put your whole team into a good position for a fight. Generally, this means flanking the enemy carries. Since your top laner usually has TP, see if they can flank one side while you ult the rest of your squad to box the carries in. Boomerang Blade may not do a ton to tanks, but it shreds carries. Note that "carries" can really be from any position (save for support). But be sure to make sure that you prioritize the SQUISHY carries. Even a 5/0 Sion still builds full tank and can't win fights without his mid and ADC. Even better, mid/ADCs usually go down quickly if you get a good flank off and focus well. Note that you can also ult when you're a ways away from a fight and your team needs you, or if your team is losing and needs a disengage. Another good way to use Sivir in the mid game is as a split-pusher. Her high waveclear and attack speed from Ricochet allows her to push and melt towers quickly. And if you get caught or ganked, just Spell Shield the damage or CC and On The Hunt to get out of Dodge.

Sivir is still strong in the late game. The utility of On The Hunt is still present, and Spell Shield can really help you reject CC, engage, and burst. Your main damage will be more based on auto attacks, due to your high crit chance, but do note that Boomerang Blade is still effective against squishy targets and is great when thrown into teamfights. Sivir does not scale quite as well as some well-known late game threats such as Twitch, Kog'Maw and Jinx, but fear not, as you DO do damage. Just don't expect to single-handedly carry your team to victory unless you're fed. However, you definitely do a number on objectives due to the attack speed buff from Ricochet, as well as defense from skillshots and global ults thanks to the ever-useful Spell Shield.

Thanks for checking out my guide! If you want, check out my other guides, mainly focused on ADCs.