I am Stardom(OD) aka Myth Helper101 on League of Legends and I currently Plat 5 while writing this and decided to make a guide on my favorite champion Ahri.
Ahri is a mobile AP Mage/Assassin who thrives in making picks as well as having good wave clear. She normally is played in the Mid Lane due to how short the lane is as well as the ability to roam to both top and bottom quickly.
Essence Theft (Passive): Ahri gains a charge of Essence Theft whenever one of her abilities hits an enemy (max 3 charges per spell). Upon hitting 9 charges, Ahri next spell heals her her 3/5/9/18 per unit hit (at 1/6/11/16) each time her passive-enhanced spell hits an enemy. This gives Ahri sustain in the laning phase as well as later in the game when needing to cap off her health.
Orb of Deceiption (Q): Ahri sends out and pulls back her orb, dealing 40/65/90/115/140 + .35 AP magic damage on the way out and 40/65/90/115/140 + .35 AP True Damage on the way back. She also gains movement speed that rapidly decay. Cooldown: 7 Seconds. Range 880. Cost 65/70/75/80/85 Mana. This is Ahri's bread and butter wave clear tool as well as giving her a good way to harass your enemies. You also use this as your primary sustain in the lane to charge her passive and use the charges of her passive too. Max this skill first!
Fox-Fire (W): Ahri Releases three fox-fires, lock on to enemies dealing 40/65/90/115/140 + .30 AP Magic Damge Priotizing Champions. Enemies hit with multiple fox-fires take 30% less damage from each additional fox-fire that hits.Cool Down: 9/8/7/6/5 seconds. Cost: 50 Mana This skill helps with some of the wave clear later in the game primarly to on melee minions as well as helping her burst on all-ins. Max this second.
Charm (E): Ahri blows a kiss dealing 60/95/130/165/200 + .6 AP Magic damage and charms an emeny that it hits for 1/1.25/1.50/1.75/2 seconds and slows the enemy that it hits. Cooldown: 12 seconds. Cost: 85 Mana. This is the reason why Ahri got good pick potential. If you hit your charm you can all-in your enemy with a E-Q-W combo which I will talk about more later in the guide. Max this last.
Spirit Rush (R): Ahri dashes towards the cursor and fires three essence bolts, dealing 70/110/150 + .25 AP Magic damage up to 3 nearby enemies, prioritizing champions. In the next 10 seconds, Spirit Rush can be cast two additional times before going on cooldown. Each enemy can only be hit once per dash. Dash Range: 450. Essence Bolt Range: 650. Cost: 100 Mana. Cooldown: 110/95/80 seconds. This allows Ahri to reposition to make it easier for her to land her Charm and makes her all-ins pretty safe and can be used to escape or turn around ganks by enemy junglers. Max this whenever possible.
Summoner Spells to use: Flash Ignite or Flash Cleanse vs Lissandra
Ferocity: Take Sorcery, Feast, Natural Talent, Double Edged Sword.
Cunning: Savagery, Secret Stash, 3 points Merciless, 2 points Meditation, Dangerous Game, Precision, Thunderlords Decree.
Runes: 9 Magic Pen Reds, 9 Armor Yellows vs AD Mids like Zed and Talon or 9 Health Per Level Yellows vs AP Mids/Corki, 9 AP Per level Blues or 9 Flat MR blues vs strong ap laners like Syndra, 3 Flat AP Quints
Common All-in Combo post level 6: R-E-Q-W with Ignite: This should at least get your enemy laner very low or dead if you land your charm. Also throw your Q in the same direction as your E for any type of all-in since your E if it hits will make the target walk into your Q dealing a large amount of damage..
Common All-in combo pre level 6: E-Q-W with Ignite: Can work but you might have to blow flash to hit your E and have your jungler around to secure the kill on your enemy laner.
If you want to get good lane control try to harass with your Q on to your enemy laner through the minions it will either make them back off a tiny bit or take the damage.
When soloing blue buff later in the game use your w whenever you get your max charges for your passive to help your sustain while taking blue by yourself.
When trying to All-in Azir after he ults: Try to use your ult to get around the Wall as if you trying to ult straight into him it will knock you back.
Enjoy playing Ahri as she is one of the most fun champions to play in League of Legends and thank you guys for looking at this guide!