Hello, I'm Neverwish and one of my first, best and favourite champions is [Ahri]. I'm sure you also will fall for her charms.

Before you start reading and disapprove this because it's not an AP build like other builds of [Ahri], I want to say that this works flawless for me.

Secondary, if you don't have eventually negative thoughts of this anymore, I also want to say that you should never follow this blindly. There aren't two the same matches, so if you need to play against a very powerful mage, feel free to buy [Lich Bane] instead of [Trinity Force],
for instance.

And as last, this is my first build so please leave a comment with your opinion in it :)

Good luck and have fun with consuming life essences from unsuspecting men :)

Pros: *Good with farming minions (especially with [Ionic Spark]) *Can get hopeless champions who try to walk away *Can escape quickly *Strong early in the game *Kills fast

SPACE

Cons: *Easily dies without mana *Needs some practice *[Charm] isn't easy to use with minions in your way

Because with this build we gain the most damage from basic attacks, Utility isn't fully used. The few AP points we can get from the Offense Masteries, also with Life Steal. Defense isn't very useful for Ahri, 'cause we don't get slain if we slain them first, right? ^^

Everything we lack when buying items, we can fill with Runes. Also, some extra mana is always useful. A few AP is also useful.

[Doran's Ring]: For a good start, it's giving you a bit more health and a bit AP to give your abilities a little more damage.
[Sorcerers Boots]: You walk faster, and your abilities don't get obstruct by their armor.
[Sheen]: More damage en mana is always welcome.
[Ionic Spark]: By far my favourite item in the game. You kill 40% faster, and after 4 seconds of attack four enimies get struck by 125 extra damage.
[Trinity Force]: Almost every needed things will be filled bij this item. Also, your attacks can slow enemies and critical damage is way higher.
[Guinsoo's Rageblade]: Ability power and attack damage are the both needed, and this blade gives a lot damage for both.
[Warmog's Armor]: At the and of the game, this is useful so you can stay longer alive, so you can destroy more turrets and inhibitors. Early in the game, this isn't recommended because it's very expensive and you don't need it really bad then.

Not every item is useful in every situation. So here are some suggestions for when it insn't going well.
[Lich Bane]: When you need to fight against persons like [Ezreal], [Lux], [Jax] or other champions who do very high magic damage, this is useful.
[Thornmail]: For when you are against champions who have high health and do many physical damage, like [Malphite] and [Alistar]. It returns a part of their own attacks.
[The Brutalizer]: Armor penetration for characters who buy many armor, like [Blitzcrank]. Nad some extra physical damage is welcome.
[Mercury's Treads]: When you're fighting against champions like [Teemo] and [Ashe}, this is useful. Blinds, stuns, etc don't last as long and they can turn a fight in your favor.
[Bloodthirster]: If kills aren't going quickly, this can be a option. High AD, and you also get a bit of their 'life essence'.

Summoner Spells: I choose for [Heal] because it has saved me many times from the death, and without mana you're also death so that's why [Clairvoyance].

Tips & Tricks:
*[Foxfire] combined with [Spirit Rush] is very powerful.
*If you want to use [Spirit Rush] to catch a enemy which walks away near a turret, first see if you have enough health to withstood the attacks of the turret and then if you have enough damage to kill him.
*If enemies try to chase you while you're walking away, use [Charm] to make them walk slower (very useful when walking near a friendly turret) and disable their abilies to attack you. Use [Foxfire] to attack them and see if you're in their attack range, without slowning yourself.