Right now they are bland in design to the point of being lesser than many other fighters and have too many weaknesses and not enough strengths to ever expect to be used. Many pro players put them at the bottom of tier lists.
Hard4Hamsters3 votesI think Noc is actually very thematic for what he's supposed to be. His ULt fits his theme very well, his E and Q allow him to chase down his victims that are fleeing from him and his W makes sure that there is no fighting back. He IS a nightmare to deal with. (he probably needs some small buffs, but I think his kit is very thematic). His kit is designed to deal with a single target, which is maybe where I see some problems as it's hard to balance a champion who has this kind of dueling potential.
I definitely agree on Aatrox though. What the hell is he? According to his lore, he is some divine champion known as Darkin who wields a living blade. But ultimately he is just a generic fighter who is a ball of stats and some built in life steal and a revive. He's not an effective tank even though you'd think he would be. He's a subpar fighter even though his kit tells you to go all in. He needs way too many stats to be good at either of those things and he's not great at either. I don't know what I would do to Aatrox to give him more dimensional play, but he definitely needs something to make him something more than an all in fighter. Maybe if his Ult gave a buff to his allies, it would be somewhat thematic as a captain leading his team into battle and would fit with his lore. (it would be kinda copy and paste of Taric Ult though) This would just be a start, but he needs something.
50000000000000002 votesIsn't Nocturne an assassin?
Kingsgrave2 votesIsn't Nocturne an assassin?
Hes terribly designed so he has to be a Fighter/Assassin instead of a full blown Assassin. His R is the only Assassin aspect.
Jaghatai1 votesHis Ult is a glorified gap-closer ... it's damage is fairly pitiful
Knight SoIaire 2 votesyou forgotthat he deals damage throygh autos
if we merely buff his damage to meet expectations, then he will be a teamwide nuke who just goes in and blows up himself and couple of enemies
his kit just doesnt fit the playstyle, and we need to consider that riot's description of assasins themselves changed making noct fit that category even less
Jaghatai1 votesHe needs some more built in tank to be relevant. And his fear should be a root. Even though the fear fits thematically, it's dumb to force someone to run away from a melee champ. The 'speed boost' doesn't really help much I have found. Usually I end up using my fear as utility for my team members more than I use it for myself.
Knight SoIaire 2 voteswell you speak more about what he needs to function with the kit he has my opinion is that we cant ballance his kit in its current form because it doesnt fit the intended role, if we buff him he should get op easily
thats why i consider major kit changes to be required
BluePolarizer1 votesAll Nocturne needs is a bigger AD steroid on his Q, bigger fear tether range and shorter ult CD,
Abyssphere1 votesIsn't Nocturne an assassin?
He SHOULD be an assassin but he has basically zero burst. He's a fighter with a long range gapcloser, nothing more. Assassins don't get spellshields, nor are half their kit AA steroids.
Boulderox2 votesproblem is when it is a ranged aa champion, nobody cares because they are ranged, but AA reliant melee champs, there kits are bland and built one way, which takes away from there viability.
personally i think aatrox needs to be a bruiser, take away his giant sustain boost when below 50% health, and make it so that he can cc more than a knockup that is very clunky. He is an ancient being of war, meant to cause fear, and devestation wherever he goes, his ult steroid is fine if it did what shyvana does, make his skills do something different when ulting, like making his w with ult cause slows on AA, his e length is doubled, and q resets on kill. or something.
he has a nice theme, but poor execution, he dies too quickly with his current health, and taking away some sustain might make him be more durable.
PalPlays1 votesproblem is when it is a ranged aa champion, nobody cares because they are ranged, but AA reliant melee champs, there kits are bland and built one way, which takes away from there viability.
personally i think aatrox needs to be a bruiser, take away his giant sustain boost when below 50% health, and make it so that he can cc more than a knockup that is very clunky. He is an ancient being of war, meant to cause fear, and devestation wherever he goes, his ult steroid is fine if it did what shyvana does, make his skills do something different when ulting, like making his w with ult cause slows on AA, his e length is doubled, and q resets on kill. or something.
he has a nice theme, but poor execution, he dies too quickly with his current health, and taking away some sustain might make him be more durable.
I think his Q should be a fear, but otherwise his kit seems okay. Maybe some base stat buffs or something...
YOLO420SWAGSCOPE1 votesWouldn't making his Q a fear be a straight up nerf? Apart from very few situations knockup is vastly superior to fear
MidEvilKnight3k2 votesThe fear would have a longer duration.
WolfChases2 votesAatrox and Nocturne suffers from the same problem.
Aatrox: If you build damage, even Janna can proc your passive. If you build tankynes you do not have damage. Nocturne: If you build damage, you will Die 1 sec after you ult. If you build tankynes you are funny....
LilxPaprika1 votesidk if nocturned were released today i'd say he'd be pretty cool. I think age has gotten the best of him. He does have a pretty straightforward kit so i guess thats the one thing that could be worked on. same for aatrox but what can you expect from auto attack based champs.
yukonl1 votesFor Nocturne, everything makes sense thematically and works alright. But his spell shield makes no sense on a champion like him. I'd rather he get some kind of other defensive steroid.
Aatrox is a rather new, but very simple in terms of his kit. First, his q needs to be uninterrupted or at least apply any CC he received after he lands. Second, his ult needs to be more than an ability that grants mostly stats.
Kingsgrave1 votesFor Nocturne, everything makes sense thematically and works alright. But his spell shield makes no sense on a champion like him. I'd rather he get some kind of other defensive steroid.
Aatrox is a rather new, but very simple in terms of his kit. First, his q needs to be uninterrupted or at least apply any CC he received after he lands. Second, his ult needs to be more than an ability that grants mostly stats.
He does nothing with his blades
Abyssphere1 votesFor Nocturne, everything makes sense thematically and works alright. But his spell shield makes no sense on a champion like him. I'd rather he get some kind of other defensive steroid.
Aatrox is a rather new, but very simple in terms of his kit. First, his q needs to be uninterrupted or at least apply any CC he received after he lands. Second, his ult needs to be more than an ability that grants mostly stats.
Is his spell shield really thematic? Or the increased AD from his Q?
The Y2J Problem1 votesI just hate how both champs are supposed to be really scary and threatening, yet neither are really all that worrisome (Noc to a degree certainly can be terrifying, but Aatrox is fairly laughable).
The embodiments of war and nightmares, both sort of left to the wayside. I mean a chick riding a pig and a fat drunk aren't bland, but it would be nice to see those two scary bastards back in action.
Teridax681 votesRight now they are bland in design to the point of being lesser than many other fighters and have too many weaknesses and not enough strengths to ever expect to be used.
I think the main issue with both of them, 
especially, is rather that they have too few significant weaknesses, and instead pay for that by just being weaker overall. Aatrox checks all the marks for problematic fighter design: he has the quad combo of gapcloser/hard CC/sustain/steroid that has been the default for so many fighters, with the additional caveat of his sustain being permanently on-demand, free and potentially massive, and at a higher level of design has several conflicting bonuses (his sustain is intended for drain tanking, which would make him good against DPS, but his revive passive also makes him naturally good against burst, so when he's successful there's no clear way of dealing with him). Right now, he tends to be fairly binary in that he either contributes very little throughout most of the game, or becomes impossible to handle if he gets a strong lead and gets to out-tank and out-damage everyone else.
I do agree that Aatrox is bland right now, though (in fact, his kit might be the most generic in the game), but he also has a ton of potential: if his drain tanking were to work without becoming abusive, he'd become a great drain tank, and if he were made to follow his lore a bit more (for example, by making his ult a team-oriented offensive buff instead of an overloaded and redundant steroid) he'd bring a totally unique contribution to the table. 
I think already makes a very unique contribution in the form of his vision denial, and just needs to play more off of his special elements and lose some of his invisible power (e.g. the AD steroid on his Q, the AS steroid on his W) to shine. There's a lot on his kit that can be condensed, I think, by following a common theme (moving towards vulnerable targets, creating zones of fear and uncertainty), and refining his abilities would likely better express what makes him interesting as a champion.
mi ramfan1 votesAatrox I can agree upon because there's really not very much going on in his kit at all and he's doomed to an eternity of either "My W is overtuned so I'm unkillable as long as I keep attacking" or "My W is undertuned so it doesn't really do anything."
Nocturne doesn't need nearly as much of a rework, though. His kit has a lot of interesting gameplay with his Q trail, E, and ultimate. Probably the best route to take if you were going to rework him would be to replace Nocturne's passive and his W's attack speed with new, more thematic effects.
Thresh 2 Fresh1 votes is a lot like 
except that trynd has an ulti that keeps him alive while he autos you to death. Nocturne just ults in, gets kited, and dies. His fear doesn't activate immediately so you need to stay close..which sounds easy but with all the mobile squishy targets you want to take down 
Etc. makes it pretty hard for him to do his job. And its not like you want to be targeting the tanks instead..
largefish1 votesNocturne is an assassin in the same way yi is labeled as an assassin, he's actually a melee carry. Yi has more survivability with is alpha strike than noc does with shroud, but noc can engage from insane distances late game and has potentially stronger steroids. If you build noc like a bruiser, he will fall off hard, and if you use your ult to engage instead of waiting for your team to engage and then ulting, you will die very quickly. Noc's shield/vision denial allows him to instagib the enemy back line, and shrug off their peel. He also spikes earlier than yi and has a very strong mid-game presence. If people stopped trying to play him like an early game bruiser or tank (NEVER build a cinderhulk PLEASE), they'd realize that he can scale insanely well into the late game, splitpush constantly, and punish ANY minor mistake in positioning instantly with his ult. TLDR; noc is not a frontline bruiser, nor is he a true assassin, he's a melee carry with stronger splitpushing/diving abilities and has a better early game/duling potential than trynd/yi. Build him with a hexdrinker, zephyr, randuins, yomus, bork, and devourer.
Maple Crusader1 votesAatrox needs to be more a bruiser who empowers his team rather than be a mediocre melee carry.
Noc needs to be overhauled. Too much invisible power in his kit.