User blog comment:Care Level/Magic Sword Ahri: A Guide to Nashor's and Lich Bane./@comment-24036535-20141230050313

I'd like the point something out: Most mages fill a very similar teamfight role as assassins: Kill an enemy damage dealer, sometimes a mage, sometimes an ADC, sometimes an assassin. Ahri fills that role as well, focusing on bursting an enemy squishy down, not focusing on sustained damage. The biggest difference between mages and assassins being: Assassins generally have no cc, but don't need any setup to kill a target, eg Talon has no cc, but can instaburst a squishy whenever he needs to, Ahri on the other hand needs to land her charm first to assassinate, otherwise her job gets a lot harder.

This is more sustained damage oriented, which WORKS, but doesn't make the most out of her kit, namely her charm, which you lose the damage amp on after a few seconds. Yes, Nashor's Tooth and Lichbane can work on her, but the AP is generally put to better use on the initial target via abilities, than used via AAs on multiple targets. The speed she can kill a squishy is still important, yes, she does might do more overall damage in a teamfights, but if she fails to kill the enemy carry fast enough, it'll kill her right back, and because it either hasn't used abilities and/or uses AAs for damage, Ahri is generally going to lose. She does still have the CDs to maintain prescences in drawn out fights with the conventional build, but like most mages and assassins, she works best in shorter fights.

If you want someone who fits your Ahri build, try Cass, Talon, or Diana. Cass has a bit of burst, and lots of sustained damage in teamfights, Talon has a TON of burst, and low enough CDs to contribute in longer fights, and Diana has good upfront burst, and can maintain damage in longer fights with her shield, passive, and Lichbane.