Archived. :-/

This build was mostly just for fun, but with some tweaks and a lot of skill, it may actually be viable. Playtest at your own risk. It probably will play just fine vs Intermediate AI, potentially even beyond. My own preliminary playtesting left me pleasantly surprised, for reasons to be explained shortly.

Boomerang Blade is Sivir's only AP ability. It scales fairly well, when you consider that AP is cheaper than AD. This means your Q will be at its strongest if you stack AP, though at considerable expense to your right-click power.

There are three notable ways to make better use of AP on a character with only one AP attack:

1. CDR
2. Lich Bane
3. Deathfire Grasp

We will make use of all of these. Since it's somewhat rough going, we'll go all-in and take a snowball build with this. In addition, we'll take a hybrid item, Hextech Gunblade, both for better farming and for other reasons to be explained later.

Indeed going mostly AP for just one skill is a bit silly. But the idea here was to do my best to make the most workable AP build I could come up with. I make no claims for its overall competitiveness. At best, it should be viable-but-precarious.

There's a good reason you don't see AP Sivir builds on here much, but for what it's worth, I find this build to be very strong early on.

Ok, I decided to up the shenanigans a little more by opening with a standard AD "triple Doran's" opening. For a few reasons.

1. It works. Triple-Doran's Sivir is an early-game beast. 9% lifesteal, 300 life, 30 damage... Pretty much all you need to lane sustainably.
2. You can pick up Hextech Revolver later on to pick up the lifesteal slack. It's up to you when. Another note about Hextech Gunblade: You make back the lost 30 AD and then some as long as you complete it before you sell all three Doran's Blades. Three Doran's = Poor Sivir's early-game gunblade.
3. They won't be expecting an AP build, and you won't give it away too early. If they stack armor, they might be in trouble. This build, in its current form, is actually an early sustained AD build that transitions into bursty AP over time.

I just tested this, and... wow. Get it early and love it. Two reasons:

1. About 110 extra Boomerang Blade damage.
2. Activated ability does 300 damage and slows your enemy. Having a hard time getting Boomerang Blade to hit in the first place? Not anymore. You stand a good chance of getting it to hit in both directions now.

Seriously, this item's name and its icon should be changed:

Instead, there should be a picture of the Pillsbury Doughboy and it should be called "Boomerang Helper".

This combo is fast enough to do it as a turret dive, if you have to. If more than one foe is around, you can still get CCed under a turret, so don't be foolish.

1. On The Hunt and/or Spell Shield
2. Deathfire Grasp (if you have it)
3. Hextech Gunblade/ Bilgewater Cutlass
4. Boomerang Blade
5. Right click

Notes:
* Spell Shield should be used for 1v1 encounters and any time your foe is not CCed. On The Hunt should be used if an ally is near.
* If you have no CC on your foe and you don't use On The Hunt, do (3) before (2) to be sure you execute the combo. On The Hunt makes it much easier to do (2) before (3) to maximize your Deathfire Grasp damage.
* Lich Bane makes just one of your right-click attacks relevant late game. Don't get greedy unless you're absolutely sure it's safe and/or you can get finish them off.
* It's better to save On The Hunt for when you have a nearby ally ready to fight for you. You don't need the attack speed, but sometimes you might need it just to get close enough to start the combo in the first place.

Your Boomerang Blade is nice, but don't count on being able to 1v1 enemies unless they're foolish enough to chase you while your Q cools down.

EDIT:

Note also that Exhaust and Ignite fit in pretty well with all this. This is good, since you don't need the gunblade too soon. However, it's even more deadly to Exhaust and then Hextech Gunblade when Exhaust is about to wear off in some situations, like when your allies need just a little more time to finish things.

Let's say you complete this build and execute your combo on a Cho'Gath with 4000 HP. Let's run the numbers.

AD:

162 (102 base + 60 ( Hextech Gunblade)

AP:

(75( Hextech Gunblade + 180( Mejai's Soulstealer) + 60( Deathfire Grasp) + 80( Lich Bane) + 155( Rabadon's Deathcap)*1.3( Rabadon's Deathcap) = 715 AP.

767 AP if you take another Elixir of Brilliance, but let's call it 715.

Deathfire Grasp damage: 4000HP*(.3+.035*(715/100)) = 4000HP*.55 = 2201 damage. Let's round to 2200.

Hextech Gunblade damage: 300

Boomerang Blade damage: .75*715 + .95*162 = 690 damage

That's for one hit. For two hits, that's 1.8*690 = 1242, or just 1240.

Lich Bane damage: 715 + 162 = 877 damage. Round to 875.

Total damage:

2200 + 300 + 1240 + 875 = 4315

If Cho'Gath's MRes is, say, 200, you'll only do a third of that, 1438. 1400 or so.

There's a minute of cooldown, so you can only consistently use, say, 690-1000 BB damage and 875 from Lich Bane, and you'll more or less be running away the rest of the time.

You do *not* do good right-click DPS late-mid-game or later. Your chasing pattern will be about staying in good Boomerang Blade position. That means you have to stay close, not just auto-attack. Your ult will help, but you should be standing *right next to them* and you should launch Boomerang Blade at them almost point blank. Remember, once you get Lich Bane, remember to only bother with right-click right after you use a skill, and no more than that. Positioning for your next Boomerang is more important with this build.

Usually this is forbidden, but you're not an AD Sivir. Once your AP starts to pick up, you can clear especially dense mobs of minions with Boomerang Blade. For example, if you're in the enemy's Nexus. Ricochet simply isn't rapid enough for this purpose in this build, unlike all the AD builds you know and love. Also, Hextech Gunblade spellvamps like MAD with this build, so go on and do it when you're low.

The idea is to have a balanced AP/AD build mid-game with some CDR. As soon as you can get a three Doran's Blades, a Mejai's Soulstealer, and all three elixirs, you're ready to start snowballing; triple Doran's and triple elixirs is a little OPed for this stage of the game, if you were fast.

You'll also want to get a Lich Bane before long, but maybe Fiendish Codex is more urgent. Between your ult and your Exhaust, your enemies should have trouble getting away from you and your allies. Hextech Gunblade actually helps Boomerang Blade more than its fair share, since the AD scaling is such that the AP and AD contributions from this item are about equally effective (before taking the extra 30% AP from Deathcap into account)

For additional killing power, a Deathfire Grasp is a nice choice. You could get Nashor's Tooth instead for CDR and early attack speed, but I like Deathfire Grasp better; blue buff or blue elixir are possibilities for more CDR. If you can't handle that, then you can use runes.

If you get far enough along for Rabadon's Deathcap, then most of your damage will come from Boomerang Blade and your Lich Bane passive. You do have CDR, don't you?

* You MUST get solo mid for this build to work. If you can't get solo mid, use a different build.
* If you're playing against humans, they should darn well know to try to gank you as soon as they see you with a Mejai's and three elixirs. You'd better know what you're doing, your team had better know what they're doing, and your team had better know what YOU'RE doing. If teamfights break out, don't die, but at least try to get assists when it's not safe to fish for kills.
* It's hard to get both swipes of Boomerang Blade to hit. CC allies would help a LOT if you can get one or two. You really need it to hit both times as often as possible, since you'll be putting all of your eggs into that basket.
* If you have a jungler, you can activate Bilgewater Cutlass to assist with mid-ganks.

Boomerang Blade needs to be leveled a lot in an AP build.
Ricochet is great for farming, but I find that diminishing returns set in when you take more than 2 levels.
Spell Shield is nice, if you time it right. Also activates Lich Bane, so a short cooldown will help.
On The Hunt is nice, even though we don't have much AD. It's still good for chasing, and it's still an excellent support skill.

They're stacking MRes:

Void Staff and Ionian Boots of Lucidity instead of Deathfire Grasp and Sorcerer's Shoes.

You're getting owned:

Abort! Try a vanilla AD Sivir like everyone else. Don't worry, AD Sivir is good and you'll like it.

You're getting owned HARD:

Take philosopher's stone and Heart of Gold for GP10. Keep your Doran's Blades for now. Try a vanilla AD Sivir, but don't sell your Doran's Blades too soon.

You're doing ok, but you don't feel confident that you can snowball Mejai's Soulstealer this game:

I don't know, Archangel's Staff or a Rod of Ages might work instead. The first gives mana regen, so that helps if you don't take Clarity. Since you won't get the CDR from maxing out your stacks, Morello's Evil Tome instead of Deathfire Grasp is another option.

Teamfights breaking out all over, things are going well, and your team has got a lot of CC going for it

Sell the Cutlass/Gunblade and get an Archangel's Staff for the AP and mana regen. You might also need a healer to pull this off.

Lately I like 12/18/0 masteries. The dodge-related stuff is nice, and it's not worth going through the whole offense tree for Havoc when some of the intermediate stuff isn't useful in this build.

You might prefer Greater Mark of Magic Penetration to what's given. I just put flat AD in there because it's a strong starter rune to go with your Doran's Blades.

Lately I prefer Exhaust for boomerang ganking, and Ignite is handy when you don't want them to heal much. Clarity is nice if you want to postpone MP5 items a lot, as is Teleport. Heal is sort of a waste, probably - you'll either get focused and die rapidly, or you'll maybe take incidental scrapes you can clean up with lifsteal and spell vamp.

Fine. Check the second build - I kind of like the MP5, anyway.

Pros:
* I didn't tell you to just stack Archangel's Staff, did I? It could be worse.
* One of the most painful Boomerang Blades possible (excepting the above)
* A challenge to play
* Hit-and-run style: CDR + Spell Shield + Lich Bane + Boomerang Blade
* Snowball build (or not)
(* Non-snowball setup is a little less conspicuous and dangerous)

Cons:
* AD evaporates mid-game, except for Lich Bane attacks
* Squishy
* A challenge to play
* Absolutely needs to be fed quickly to do decent damage beyond mid-game
* Hit-and-run style: very poor when cornered and outnumbered.
* Snowball build
* Conspicuous gank target
* Needs tanking and CC
* Late-game pushing isn't as strong as AD builds, but still good-ish