I know I still have like a thousand Legion comics to review, but this idea got stuck in my head.
How would I rank the Legionnaires, from weakest to strongest, in a fight against the others?
A few ground rules first:
A) Original continuity, up to volume 3. I might do something like this for the reboot once I’m done with it, sometime in the 23rd century.
B) This is only a ranking based on who would defeat the most Legionnares in a one-on-one fight, and most definitely NOT about who is the best character.
C) The Legionnaires retain knowledge of their teammates, but no “prep time”.
D) The no killing rule still applies, otherwise it wouldn’t be the same character. Imagine the Legionnaire they’re fighting is mind-controlled or possessed.
This is just for fun and OCD, so let’s throw in the honorary members and the Substitutes.
Adding a couple of special exceptions, that leaves me with… 56 entries.
What have I gotten myself into?
D TIER
The worst of the worst
#56: Pete Ross
#55: Rond Vidar
They don’t have any actual powers or any combat experience. However Rond’s immunity to his father’s hypnotism MIGHT give him some very minor protection against illusion casters and telepaths, so I place him above Pete by the slightest of margins.
#54: Night Girl (in daylight)
She will be much higher in the ranking if the fight is during the night! But if she’s exposed to even the slightest amount of sunlight, she’s an ordinary girl. Even with this handicap I still place her above the honorary members because she has SOME combat training and a Flight Ring.
#53: Color Kid
The only character in this tier who gets to use his power in a fight. An almost completely useless superpower, but he HAS used it to blind his opponents… so he might have the slightest possible chance to take advantage of this to knock out a powerless Night Girl. 
#52: Dynamo Boy
Yes, I still insist that he counts as a former member despite how terrible his story was. In case you’re lucky enough to have forgotten him, he has several gadgets that do extremely random things. Most Legionnaires would easily disarm him because he could do anything, but I think he could defeat a couple of the weakest. 
C TIER
Barely useful powers
#51: Command Kid
The OTHER terrible member from an awful story that only I consider a legitimate member!
He has illusion powers, but he doesn’t seem capable of using them with the same versatility of Princess Projectra. Possibly better than Dynamo Boy, which is the highest praise anyone’s ever had for Command Kid. 
#50: Infectious Lass
Hear me out on this. “No killing” is still in effect, so it’s not like she would instantly give someone a terminal illness. I’m basing this on the idea that she’d start out with a minor illness to inconvenience the opponent, and any Legionnaire worthy of the name would power through it. Admittedly Color Kid or a powerless Night Girl could do the same, but unlike them I have no doubt that Infectious Lass could defeat the crappy Dynamo Boy and Command Kid.
#49: Princess Projectra
Her power-up into Sensor Girl WILL give her a higher spot in the ranking, but if you know she’s going to cast illusions the best she could do is disorient you better than Color Kid. And she’s never demonstrated to be able to hold her own in a brawl.
#48: Matter-Eater Lad
I go back and forth on whether to place him higher or lower than Projectra. But there are very fringe cases where his power could be of minor use against some Legionnaires.
#47: Dream Girl
Unlike her reboot and threeboot counterparts she doesn’t incorporate precognition into her fighting style, so her power is practically useless in a fight. But she’s demonstrated she CAN fight on her own, unlike Projectra, and unlike M.E.L. she’s shown to be very creative in using her Flight Ring. 
#46: Triplicate Girl / Duo Damsel
What’s better than a girl who’s kind of good at fighting? Two or three girls who are good at fighting.
#45: Invisible Kid II
None of the people below his ranking have other ways to sense his presence and they’re all as tough as a regular people.
#44: Invisible Kid I
I rank the original slightly higher because he has more experience. He lacks his successor’s random teleportation power, but it’s unlikely to be part of the fight anyway.
#43: Shadow Lass
Most definitely a better fighter than the invisibles, and she could level the field by making them unable to see her by creating darkness. A nightmare for the penciler to draw this fight, though. 
#42: Stone Boy
I’m shocked he’s even this high, but once he turns into stone… what can the people ranked below him even do? The fight would end in a draw until the opponent tires out. Potentially Matter-Eater Lad could eat his stone form, but the “no killing” rule is still in effect.
#41: Chlorophyll Kid
Try sneaking up on him when he creates a forest around himself. And he’s used plants to break open a freaking mountain, so Stone Boy is toast. 
B TIER
Actual superpowers
#40: Insect Queen
Her transformations are VERY versatile and unpredictable. She’d eat through anything Chlorophyll Kid can throw at her, and unlike M.E.L. some of her transformations can attack at a distance.
#39: Fire Lad
Fire beats insects any time of the day.
#38: Kid Psycho
The force field he creates is supposedly indestructible. But we’ve only seen him use it to create a static barrier, so anyone with enough mobility to get around the barrier would take him out.
#37: Elastic Lad
Elasticity is an underrated power! High versatility and mobility, so even an idiot like Jimmy Olsen should be able to do SOMETHING with it.
#36: Timber Wolf
He’s no Wolverine, no matter how much modern writers try to force him into the role, but he’s still sharp enough to work his way around invisibility and illusions. He’s also unbelievably agile and way stronger than most remember. He doesn’t rip Elastic Lad to shreds thanks to the “no killing” rule, but he wins this easily.
#35: Karate Kid
We know he can hold his own against opponents FAR stronger than him, so I believe he’d defeat Timber Wolf and tie Elastic Lad into knots. His lack of ranged attacks and limited speed prevents him from getting any higher, though.
#34: Bouncing Boy
Even assuming Karate Kid or Timber Wolf manage to hit him: would they actually do ANY damage whatsoever? He’s basically immune to brute force attacks unless they’re at Superman levels. And being hit by him bouncing around is no joke. 
#33: Porcupine Pete
His quills are potentially a problem for Bouncing Boy, and since he can shoot them he does have ranged attacks that Timber Wolf and Karate Kid lack.
#32: Night Girl (at night)
Now we’re talking. If she gets her super-strength (which is supposedly not that far from Superboy’s), and presumably SOME level of invulnerability as well, none of the people below her stand a chance.
#31: Light Lass
#30: Star Boy
These two share the same “instant win” condition: if they make the opponent too light or too heavy to fight before they’re hit, they win.
And they don’t need to see their opponent to do this, so they have an advantage against the invisible and illusionists.
Only people who have powers that counter their mass manipulation, that have powerful ranged attacks or that are way too strong to be slowed down stand a chance. I don’t think Timber Wolf or Night Girl are strong enough for this.
I place Star Boy slightly higher because he has a better track record at being useful than Light Lass.
#29: Dawnstar
Speed is her main advantage, and since she’s way tougher than she looks most people on lower ranks wouldn’t do much damage. Physically weaker than Timber Wolf who could probably catch up with her in a closed environment, but it likely helps her get around Light Lass and Star Boy.
#28: Tyroc
He has such a range of weird and unpredictable powers that most people on lower ranks would have trouble to keep up. Plus teleportation gives him the best mobility.
#27: Colossal Boy
He’s a huge target, but I’m guessing he’s stronger than Timber Wolf and he has way more experience than Night Girl. Can probably shrug off anything Karate Kid or Bouncing Boy throw at him.
#26: Sensor Girl
Told you she’d be higher after her power-up. Leagues above the other illusionists, especially thanks to being able to take away other people’s senses. Acting on her own, however, she doesn’t have any means to actually harm most of the people I rank above her or to withstand their weakest attack.
#25: White Witch
The Legion’s glass cannon. Given prep time she’d probably rank higher. Still, VERY unpredictable and I’m guessing her mystic senses give her enough protection from Sensor Girl long enough to use a spell.
#24: Chameleon Boy
In my opinion, THE most versatile Legionnaire. Take all the advantages of the invisibles, of Insect Queen and of Elastic Lad, and you still haven’t reached everything Cham can do. Adding to his creativity and experience, I don’t think White Witch can keep up with him. Plus he can probably come up with weird animal senses Sensor Girl doesn’t even know about.
A TIER
Unfair superpowers
#23: Magnetic Kid
Has a couple advantages over Chameleon Boy: higher range and magnetic barriers, which potentially shield him from lower ranks. Probably more susceptible to Sensor Girl’s powers, but she has no defense against anything he can throw at her.
#22: Tellus
Telekinesis keeps lower ranks far enough to avoid trouble. He tends to favor that to telepathy, but if he does use it, add a slight advantage over Magnetic Kid.
#21: Polar Boy
Lower ranked people would have trouble getting close without being frozen, while also avoiding any ice projectile he throws. Ranked higher than Magnetic Kid and Tellus thanks to vastly superior experience. 
#20: Lightning Lass
#19: Lightning Lad
Nobody below them can withstand their electric blasts if any of the twins gets serious. Timber Wolf and Dawnstar might be fast enough to avoid the first strike, but not for long and they both lack range. Ranking Garth above his sister because he’s had more experience with his powers.
#18: Cosmic Boy
All the advantages of Magnetic Kid plus WAY more experience and a better handle on his powers. I think he should be experienced enough to have a counter against electricity, telekinesis and coldness without thinking too much about it.
#17: Chemical King
Another guy with “instant win” conditions. But unlike Light Lass and Star Boy, few Legionnaires have an actual counter if he uses his powers to screw up with his target’s body. Plus his power does work at a distance, even if we don’t know how much, and he has used his power on himself to gain short-term super-strength. 
#16: Ferro Lad
The same advantages of Stone Boy, except A) he can actually fight while invulnerable B) he’s WAY tougher C) he’s strong enough to hurt Superboy.
He lacks range and most likely he has trouble with the invisibles and the illusionists, but as long as he’s in his iron form they can’t actually do anything to him.
I assume Chemical King’s power doesn’t work on him once he’s made of iron. And while CK can make himself strong enough to break Stone Boy, Ferro Lad is way tougher and not immobile.
Magnetic Kid and Cosmic Boy are a tough opponent for him, especially the latter, but I think Ferro Lad has this considering his strength.
#15: Shrinking Violet
Anyone on a lower rank would have trouble touching her when she goes sub-atomic or have any counter for her jumping inside their ear to knock them out. Possibly Ferro Lad, but he has no way to actually hurt her when she’s microscopic.
#14: Brainiac 5
His force field protects him from the powers of on a lower rank, as well as pretty much everybody above him as well.
He lacks a ranged attack, but he can probably come up with something while the opponent wastes time trying to get around that force field.
Unless you have a specific counter or you’re too tough for Brainy to quickly come up with something to hurt you.
#13: Quislet
Same advantage of Shrinking Violet: when he gets out of his ship to possess an object, even if you destroy it Quislet can just jump into another and you can’t do anything against his real form.
Plus we don’t even know if he HAS any senses to trick, and anything Brainiac 5 builds to use against him immediately goes to Quislet’s advantage.
#12: Phantom Girl
Nobody ranked lower can literally touch her, and they have no defense against her partially materializing through their bodies. The canon isn’t clear about whether she can phase through Brainiac 5’s force field, but I’m assuming she can.
She might not be able to hurt Quislet directly, but the opposite is also true so it’s a likely tie.
She doesn’t have a counter against invisibles and illusionists, but again: they can’t touch her. The only ones who could give her trouble are White Witch with a specific spell or Tellus with telepathy, but she has way more experience.
#11: Sun Boy
Just like the lightning twins, most people on a lower rank have no protection against his power. But the magnetic brothers are weak against heat, Shrinking Violet and Phantom Girl would be burned once they go into offense, and only 3 Legionnaires ranked lower are invulnerable to his powers.
Except both Stone Boy and Ferro Lad wouldn’t last that long once he gets serious, and Brainiac 5 would have trouble coming up with something that can withstand the heat of a star.
#10: Blok
All the advantages of Ferro Lad. Definitely slower, but he doesn’t have a specific weakness against magnetism, I think he’d be more resistant to heat, and his biology likely means that the instant win conditions of Chemical King, Shrinking Violet and Phantom Girl don’t apply.
No ranged attack and possibly very vulnerable to invisibles and illusionists, but what are they going to do to him?
S TIER
Simply overpowered
#9: Star Boy (original powers)
He started out with Superboy-level powers, including a couple more. Nobody on a lower rank can actually hurt him, and he has many options for long-ranged attacks. Prevented from being higher because he doesn’t keep these powers for long.
#8: Wildfire
All the advantages of Blok. Not as tough and probably not as strong, but with one of the best long ranged attacks and impressive speed. Quislet has a chance if he possesses Wildfire’s suit, but he can’t keep it permanently so it would essentially be a tie. Brainiac 5 would have no problem withstanding Wildfire’s blasts or come up with something to harm him, but his range and speed probably close the gap.
#7: Ultra Boy
Superspeed is always an unfair advantage. Combine that with invulnerability and super-senses, and Ultra Boy would have to switch powers once or twice at most. Probably doesn’t even need to switch to defeat Blok, and tons more experience with Star Boy with this kind of powers.
#6: Element Lad
The best “instant win” power up to this point. Ultra Boy would get the drop on him if he immediately switched to superspeed, but he doesn’t tend to rely on that specific power as the first move.
Blok and Wildfire’s suit can most likely be transmuted into something else, and even if Brainiac 5 is still protected by the force field Element Lad can turn anything coming his way into something harmless. Lower ranked Legionnaires would have trouble getting past an Inertron barrier, but it could potentially be a tie against Phantom Girl.
Anyone else gets knocked out by changing oxygen into sleeping gas. 
#5: Saturn Girl
Telepathy is just unfair. Against anyone else ranked lower, the fight ends the second it starts. The exceptions are Ultra Boy if he immediately switches to superspeed, or Quislet if she has trouble using her powers against such an unusual mind. I find both those options unlikely.
#4: Nemesis Kid
His power is literally “I can’t lose in a one-on-one fight”, except he HAS lost before. But I don’t think Sensor Girl can pull off the same trick twice, and while I could see him giving himself immunity against telepathy when fighting Saturn Girl… would she have what it takes to then defeat him in hand-to-hand combat?
Possibly, but we don’t see her fight with her fists enough to be sure.
The only other Legionnaire who has defeated him on-on-one was Duo Damsel, but it’s such a specific condition that I don’t think would justify ranking her higher.
In fact, there’s only one other superpower that screws over Nemesis Kid’s chances… and it just happens to be shared among the three most powerful Legionnaires.
#3: Supergirl
#2: Mon-El
#1: Superboy
Superspeed is just unfair. Most characters without it, including Nemesis Kid, wouldn’t have the slightest chance to react before being hit. And unlike Ultra Boy, these three are FAR more likely to incorporate superspeed into their initial attack.
Add invulnerability, a stupid amount of versatility, a ridiculous amount of long-range attacks AND the tendency to use all of these advantages at the same time… it might be predictable, but there’s no question these three are above everyone else.
Which is not to say it’s impossible for other Legionnaires to defeat them: Saturn Girl and Element Lad in particular have instant win conditions against them… but superspeed makes it VERY difficult to use them in time.
So the only question is ranking those three.
Supergirl is unquestionably not as strong as the other two (despite still being stronger than anyone in the list except possibly Ultra Boy or Star Boy with his original powers).
I place Superboy on top because, while Mon-El has been around for a thousand years, he has less experience using his powers.
Mind you, this isn’t meant as an absolute ranking… you CAN write a story when any of these Legionnaires defeat another.
Well, within reason.
I’m not betting on Color Kid defeating anyone.