Fixing Ahri for competive play
For anyone who plays a lot of Ahri you quickly learn how relent you are on her 'Q' (Orb of Deception) it's her poke, it's her primary source of damage. And playing her so much you can quickly realize that during laning being able to dodge just the return damage is more than enough to change the game. So unless your at max range it can be difficult to get both procks of damage when a sidestep can cut that damage in half, granted you do have some control on the return path to assist with that but think about it, I already hit you, with the first case, why do i have to dance to get the more important return damage, why do i have to hit you twice when you already 'outplayed' you (not quite right but close enough). There's more, kit wise unless your not in lane you have to get close to your target in order to burst... like really close. Her 'w' (Fox-Fire) targeting has always been crappy (point blank usage but targeting minions over champion) but on top of that the range is about her basic range (a little more i think), that means only the front most Fox-Fire will go at the enemy, the remain need to spin the distance to enter in range (which during laning is more likely they just target minions). And team fights is the worst since you're likely only going to be able to 'pick' targets with your 'Q' unless they get out of position or you can somehow flank (which is dangerous to try and do during a fight). Next ability, which is a vital part of her kit is of course, her 'E' (Charm). This allows her to win trades so long as a clear window is available, just fine ability during lanning, but against team fights, that reliability is destroyed. Again you can try and flank, but again it's dangerous and more likely just gonna end with you singling yourself out, and or getting stuck in the middle of the enemy team because you need you 'R' (Spirit Rush) to quickly re-position. As for her Ult, its what give her a lot of the kill potential, not so much for the damage, but the utility it provides. Gap closing, dodging, retreating, engaging, it's very versatile ability, but the most important use I find is using it to re-position to get that second half of her 'Q'. Now I mentioned how important landing the entirety of the the ability (for her 'Q') but it can be quite easy to dodge the second part of damage, nullifying a lot of her damage. Second, a QSS can make it so even if you get the 'E' + 'Q' combo down then can still dodge it not only that during laning phase the duration is to small to hold them there for the 'Q' return path (thou this depends on distance to target and how quick you are with the simple combo), if they a really motivated they can flash out too.
Summary: Your damge on the 'Q' is Ahri's primary and most reliable source of damage (due to things mention above), but it's pretty easy to deal with. Playing against her countless times (and as her) I've seen this fact abused by simple dodging the return damage. And with a QSS later in the game in can prevent assassination, that's important that damge is. And to already landing the initial damage, then needed to get the return as well, you already did good by landing it in the first place, why ruin it like that.
Conclusion: The best solution I can think of is: A) Return the bonus damge on her 'E' (Charm), sort of an indirect buff. But to be fair if this was done it would be like a max rank gain an extra ability so her lanning isn't too strong. B) Speed up the return animation of her 'Q' (Orb of Deception). Which can cause some problems against mobility champions but I think would be negotiable. That said making the Ult 'R' (Spirit Rush) more spam able would help, or to an extreme give her an extra change. Because as a mobility champion, she's lacking. This extra change will help her transverse terrain without to much lose of only have 1 or 2 left because of it. C) Switch around the damge on the 'Q' so it does true damge first, then normal AP damage D) Address team fights instead and tweak her abilities scaling. I'd be intresting if they made it so three Fox-Fires would spawn for each enemy champion within range (else just 3), but as a long time Ahri player I'd hate to see this. Purely because it just doesn't look good, thou the damge would be appreciated
What I'd Like to See: Personally I'd like to see her 'E' get a buff. This would help a lot against against the number one way to counter Ahir, build a little HP. Honestly just a little HP can go a long way, combine that with a little hard CC or just a QSS and you turn on her really easily, and I feel that this would be the most affect way of dealing with it so building a single item doesn't destroy her pick play style. All this said there is a build that can help, but you still need to be ahead in order to assassinate (assuming the have a QSS for your charm or is just somehow able to dodge the return strike of her 'Q' they could still potentially live even with that)
FYI: I am indeed an Ahri main, so I probably have some bias towards her, that said I believe what I said is in fact true and should be at least considered. That said since more are playing her she's likely to get some nerfs.... thanks Riot. Pls fix the bugs at least before you do.