Ahri ADC
http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1452712299/200116563
First off, I know. I'm Bronze I. This is only one game. I didn't even do that well.
Anyways, let's start off with the pro's as ever.
Pros:
Stats:
Better base AD than other off (and on)-meta ADC's
Ahri: 50 Jinx: 50 Corki: 48.2 Quinn: 48 Urgot: 48 Ezreal: 47.2 Caitlyn: 47 Miss Fortune: 46.5 Draven: 46.5 Lucian: 46 Twitch: 46 Varus: 46
Competitive AD/level: 3.0 (Same as most ADC's) Competitive Range (550, same as most ADC's) Competitive Base Attack Speed: 0.668 (Higher than all meta ADC's besides Draven and Twitch (0.679))
Abilities:
Q: Early-game assist with wave clear and slight harass potential; Combos with E; Part of full combo
W: Use to proc Ahri's passive or for harass while chasing/being chased; Combos with E; Part of full combo
E: Used to initiate full combo, to catch out enemy ADC's, to harass; Used to disengage and escape from ganks; Initiation of full combo
R: Used to engage/dis-engage; Combo's with E; Part of full combo
Early Game
Ahri is squishy, having a low base HP (380). She needs to stay back at level 1 and farm with Q or go for full harass by strategically placing her E to catch out supports or enemy ADC's.
Mid Game (Post level 6-8)
Assuming you've survived Early Game without feeding or getting behind too far, Ahri can become a pick machine. Using her ult to initiate ganks/engages, placing an E (Max first) correctly can lead to 2 seconds of free AA's, or 2-4 AA's. That's invaluable to initiating, and Ahri can use her R three times to dodge abilities/chase/disengage.
Late Game
Ahri, depending on your build, can become an initiator or an assassin, with her 2 second E charm, and make OR break teamfights. Her R is her mobility and her Q and W account for either healing or harassment, depending on her your build of Ahri.
Cons:
Stats:
Less base HP than most ADC's (380) Less Attack Speed/level (2% compared to 4% of other ADC's) Others :P
Abilities:
None of them scale off of AD, meaning her ability harass is weak early and mid game. Ahri relies on her E to initiate good combos and the high mana cost means that she cannot waste her abilities early or she'll be left with no escape or initiation. Consider buying mana items or a Manamune.
Early Game:
Oh man. Ahri is weak early. She needs to be safe and farm, leaving the crazy plays for her support.
Mid Game:
Still not the strongest because she relies on E and R. Her Q and W still don't do much damage and don't provide CC, unless AP is bought.
Late Game:
Ahri at this point is not very weak unless caught out, like other ADC's. Again, only two useful abilities for duels and teamfights.
Overall, I think that she has potential to be a devastating ADC and she is one of the top contenders for anyone who wants to break the meta in the botlane, or just want a new challenge. Please give me your thoughts ^~^.
or

With BORK it's does more damage when used with W.
or
it's really up to you. I go
NEVER go Shiv, it's useless on Ahri since you really depend of teamfighting, and picking people off.
Just because.