User blog comment:Kagiretz/Champions Powers, Advantages and Disadvantages ( Nerfs )/@comment-12314620-20140223232158

With Blitzcrank, Caitlyn and Katarina the "problems" you see with them are a part of their core identity and if riot were to touch them they would have to be really careful about it. At the moment Caitlyn isn't even that strong outside competitive play and Phreak  has stated that in order to make people stop picking Caitlyn they would pretty much have to destroy her core identity. Blitzcrank is also very two dimensional and predictable and is terrible in lane if you know how to play against him, in most comps Thresh is practically Blitz v2.0.

Jinx is a bit problematic but her Q isn't the source of the problem, it's the upfront burst damage her ult offers at point blank range and flame chomper strength in lane. Both of those are currently going through nerfs in pbe so we might see some fixes next patch. Botlane is currently very warped by the power of top tier adc:s, holy trinity of supports and strength of dorans shield (as well as very bad itemisation in terms of gold generating items, coin too strong or edge/relic too weak). After these are adjusted I think bot might get a bit more diverse again.

As many have pointed out before there's much you can do against Fiddle. In low elo he's strong because people don't invest in vision and aren't familiar with his play pattern and strengths. He isn't bad but using drain for example is so risky you need to have some sort of reward for using it (you can't move, you can be interrupted...)

LeBlanc is a problematic champion: Not many players can play her to a great success since she requires a good amount of coordination, mechanical skill and cleverness to work well. She also isn't the best teamfighter. Therefore her winrate isn't anything spectacular. The few players who have nearly reached LeBlancs skill ceiling however can make her feel almost unstoppable. Because she seems to be doing so well in pro level there might be some tweaks. Still she's very hard champion to play well so I don't think riot would touch her too much.

Fiora: Very weak in current meta, pubstomper, suffers from the same problem every melee carry suffers from. Personally I'm much more afraid of a good master Yi than I am of a good Fiora.