For some reason, Amumu's never been easy for me, but I haven't jungled with him yet.

Really has to be characters that rely heavily on skill shots or have complicated kits..

Lee sin
Nid
anivia
vayne

were all difficult imo but that said I only have a handful of games with any of them.

I would also add shaco but feel like I will get downvoted for that! The only time I tried him in classic was a massive pile of fail and I just stuck to playing him in dominion. He is hard because you either gank well or you fall way behind without much middle ground and add no value to your team because a shaco cant just walk out of jungle to mid game and contribute like other junglers can, they need to own early for the lanes to get fed.

Other champions like eve & teemo are less about difficulty and more about viability. Really good players can do well but I feel like that has more to do with being good in general and they could do just as well if not better with another champ. Example: A lot of teemos build atk speed for the on hit damage - well kogmaw can do the same thing, has better range and better on hit, a permanent 30% asp buff vs teemos 40^% for a few seconds after stealth. That said, dont get me wrong it is fun to roll teemo bot lane with another ad and harass the **** out of the other carry with poision + blind to deny them farm. I did nothing but that and ganking mid as 'support' teemo and went 6/1 early game.

If you are good at lee sin on the other hand you can be an unstoppable wreaking ball ganking from jungle.

Malphite.

If you know what I mean.

Personally I think some of the hardest APs to learn are:

(And by learn I just mean you need to practice them quite a number of times to get them to their full potential.)

Orianna: Need to know by heart her ball's return range and ult range. Don't forget to use her shield for damage
Victor: Has amazing burst but is difficult to guarantee that stun or death laser damage.
Gragas: Gotta land them barrels, and them charges, and them ult barrels or they get away
Cassiopeia: Even pros admit that no one has really hit her skill cap yet.
Anivia: One of the hardest stuns as it is so slow, and a wall you need to get right.

Also any AP with mana issues may take practice for playing them if your blue got stolen.

I also would like to add Heimer to my list because while his rockets and turrets are some of the easiest things in the game a great Heimer needs to land his grenade which is easily one of the hardest skill shots in the game to land. Also so squish an is always pushed, not dying while doing this takes practice and awareness (and a good grenade.)

.

I dont know why ahri isnt in the hardest champs list.

Katarina? Are you kidding me?
I would put her at easiest champion. Press "r" to win, then after 2 or 3 kills press "r" again....

A hard choice for myself... considering so many variables. Such as players ability to be able to land various skillshots... But personally, for myself the list is;


Lee Sin: A good Lee is quite able to do things no other champ can, and if he really is that good it will be very hard to lock him down. The Second part to all his normal skills make him one of the most versatile champs around. But the fact that you actually have to know what you're doing with him makes him pretty hard/


Orianna: A very overlooked champion. She takes a serious amount of practice to get down just right, like knowing her exact range on every single skill. (I myself have to work on timing my ult just a bit better..) She excels as AP mid or a Support, so there is alot of difficulty between the two roles.



Nidalee: Let's face it, we've all faced Nid's that have just wrecked our face with those spears. And when said Nid has 700+ AP those spears hurt, alot. Her ability to function in both Human and cougar form leave alot of options available, plus her Attack Speed increasing heal? Lets her fit almost any role. Each one takes a different amount of skill to perform properly.


Karma: Firstly, who? But secondly, Karma is one of the more versatile supports out there, but she isn't just a support. I've seen a couple karma's go into mid and just dominate it. With her Unique Mantra system she takes timing and skill when to know how to drop one charge for a skill.


Anivia: Ahh yes, the famous blue pigeon. Anivia is a heavy burst champion that alot of players underestimate, understandable if the person in question is not too good with her. But a good Anivia is quite able of putting most other champions to shame, her Q is an AoE stun, she has quite a large wall, her single target nuke that melts faces, and her flashy ult. Each part of her making for interesting combinations in a team fight. Quite interesting but reliant on ability to land her stun.

Ezreal
Nidalee
Xerath/Draven-require good strategy, especially in positioning
Shaco-lot of mind games involved w/ ult
Casseiopiea has to be the most difficult in the game currently

galio, support janna, especially karthus (jk lol), eve, karma has a confusing burst sequence, urgots has short AA range and high dependability on mana and is most likely the hardest champ to use lategame due to all the specific champs you need to target/cripple/snipe/slow, I've heard cassiopeia is another one but I dont play her personally so I dont know for sure. basically anyone with lots of skillshots and a complicated ultimate could be labeled as "hard"