Yea this RT is a bit different to usual stuff I'm used to putting out. The question is, of course, why I'm doing four characters at once. Well, they don't have enough individually to be in their own RT, so I'm throwing them all together in a mega thread, where the connecting chain between all four of them is that each are teambusters, and each are currently forgotten and underrated. The format might be a bit different, but it's should work.
#1: The Jest Master
After losing his own planet to a cosmic disaster, the Jest-Master now tests the legitimacy of other planets by subjugating them to his powers to induce insanity to the masses. The guy's only been in one issue (Justice League of America #81) so the lack of citations here is only because it'd be pointless.
Insanity Manipulation
Jest Master can turn a entire planet mad just by passing it in his spaceship, reducing the citizens to crazy dudes.
Batman moments after entering the planet where Jest is already feels strange.
Scan 1/2- Turns Atom and Hawkman against each other, to the point that Hawkman tries to kill him.
Scan 1- Hits Flash with mist that overloads his senses for hours.
Scan 2- This kept Flash out of action for about a hour or so, in which he is eventually able to recover. This quick recovery might be influenced by his Speed-Force enhanced metabolism.
Scan 1/2- The Justice League lose their sanity and all sense of time while outside Jest's ship, and are incapable of stopping him. Atom only survives this experience due to being small and not being exposed to the ship.
Knocks out Atom by throwing his insanity gas at him.
Strength
Jest Master has taken over four whole worlds using his powers, and could have taken over the galaxy if left unchecked.
Technology
Jest's ship can influence and amplify his existing abilities to induce madness to the point that he can drive entire planets mad.
#2: Spaceman X
Created by a mysterious alien, Spaceman X was designed to feed off disasters that occur and transfer the energy to its creator. To do this, the robot pretended to be a hero, which worked for the general public: not for the JLA, through. They eventually tracked down its creator and defeated him, through not without major grief.
All feats here are from Justice League of America #20. Spaceman X didn't appear anywhere else, so no need for citations.
Durability
Scan 1/2- Aquaman, Wonder Woman, and Green Arrow all try to hurt him, does nothing (Justice League of America #20)
Spaceman X drains energy from other people to make itself more durable, allowing it to amp its already existing durability. Here, powerful individuals like Sliver Age Green Lantern and Wonder Woman are left powerless after a short encounter with the robot. This showcases powerful and effective manipulation of energy.
Strength
Tugs and keeps a ocean liner at the harbour (Justice League of America #20)
Stops a dam from overflowing and carries a huge building casually (Justice League of America #20)
Creates a giant tidal wave to stop another tidal wave from destroying all of the islands of the Caribbean
Is strong enough to swat away all of the Sliver Age JLA (barring Manhunter and Superman) with a single slap
Technology
Scan 1/2- Can also absorb energy from disasters, which makes the creator of Spaceman X unbeatable to the JLA and virtually unkillable.
#3: The Equaliser
A ancient alien obsessed with balance (who else does that remind you of?) The Equaliser invades planets, and uses his powers to make them completely and utterly balanced. And when I mean balanced, I do literally mean that....
Again, he's only in one issue (Justice League of America #117) so individual citations are not needed.
Energy Manipulation
Creates a energy blast strong enough to wipe out the Sliver Age JLA completely, stops himself because it wasn't balanced to their own combined strength
Scan 1- Equalises a blast from a guy who had stole the JLA's powers and matches it in power.
Scan 2/3/4- This is also impressive because said dude was able to fight with the JLA pretty well for himself before stealing their powers.
Equalisation Manipulation
Turns everyone on a planet exactly as equal as each other in physical stats and capabilities (so Hawkman lost his powers and shrunk to the same size to everyone else on the planet). This process was basically done in a instant, and there was no way to correct the process after it had occurred.
The equalising is caused by very infectious germs which could have infected the entire galaxy in time. Hawkman and the JLA can't cure it for his population either (despite having Batman and Atom around) forcing Hawkman to be incapable of returning to his home planet out of fear of getting it again.
Can also manipulate matter, like when he removed Hawkman's ship from existence by first analysing it using his ship and then removing the spaceship. (also matching another blast by him, very impressive)
Equaliser himself has super OCD and will correct even small irregularities using his tech, also counter balances a combined energy attack by the JLA again with no trouble at all.
#4: Invictus, The Guardian of Angels
Invictus was a zealot that was left in chaos after being attacked and his planet conquered by Larfleeze. Swearing revenge, he created his own solar system (a replica of the one he lost) and went after him. The New Guardians would be slapped around by him until they were able to remove the energy source of his power away from him, which left him powerless in the process.
Considering he's actually appeared a few times, I'll be giving citations now.
Durability
Casually sits in a large sun with no problem (Green Lantern- New Guardians #5)
A attack by a Guardian only pisses him off and he sends him flying with a energy blast, as well as destroying Krle's construct armor (Green Lantern- New Guardians #8)
Laughs off Saint Walker attacking with double his average strength and knocks him on his ass with a quake (Green Lantern- New Guardians #7)
Scan 1/2- No sells Krle's titanic ship construct, the impact of the explosion he creates one shots all of the New Guardians (barring Saint Walker) and knocks them out. (Green Lantern- New Guardians #6)
Scan 3- This is clearly seen as the case even next issue when all of their unconscious bodies are displayed.
Scan 1/2- Tanks multiple New Guardian members inducing Krle, who is only stopped after being convinced of not attacking them further. As you can see from the second scan, everyone is pretty shook up and not in a good condition at all. (Green Lantern- New Guardians #7)
Scan 3- Krle openly states that the New Guardians combined would have been wiped out by Invictus with little trouble.
Scan 4- This encounter leaves the group with little energy left, as even Krle for all of his strength only has 7% of his ring energy left after the fight with him. Green Lantern- New Guardians #8)
Scan 1/2- His performance is far better than Larfleeze, who was restrained and defeated by the New Guardians and a a single outburst by a Guardian. This shows that Invictus by direct comparison is stronger than Larfleeze. (Green Lantern- New Guardians #8)
Energy Manipulation/Projection
Busts a entire planet casually with a single blast (Green Lantern- New Guardians #8)
His energy is felt through a white hole by a Guardian, who regards it as "powerful". (Green Lantern: New Guardians #5)
Larfleeze states that none of the New Guardians (including Larfleeze) can take him on (Green Lantern- New Guardians #8)
Not only no sells Bleeze's fire, but seems to drain it into himself (Green Lantern- New Guardians #7)
Scan 1/2- One shots Fatality and Murk with one blast casually (Green Lantern- New Guardians #6)
Overpowers the Blue Lantern ring easily (which has in the past been able to deal with both Red and Black Lanterns) (Green Lantern- New Guardians #6)
Powerful enough to rip a hole in his universe (which is what creates the white hole in the other universe) (Green Lantern- New Guardians #7)
Speed
Catches Bleeze mid blitz and overpowers her in a choke (Green Lantern- New Guardians #7)
Strength
Beats the crap outta Larfleeze while by himself, drawing blood from his beatdown (Green Lantern- New Guardians #8)
Fodderises Arkillo in a panel (Green Lantern- New Guardians #7)
Scan 1/2- Is powerful enough to dominate Arkillo in combat casually while holding back. (Green Lantern- New Guardians #6)
Scan 3- When he actually tries, he takes him out with one energy blast.
Technology
Scan 1/2- Builds a ship the size of a entire solar system, as confirmed by Krle himself multiple times (Green Lantern- New Guardians #5)
Scan 3- This entire thing was created by Invictus by his own hands and energies.
Each planet apart of the ship is the size of a actual real world planet (Green Lantern- New Guardians #5)
The ship has more gravitational pull than a sun, and actually threatened to drag other planets around it into the creation, hence why the Guardians were called. (Green Lantern- New Guardians #5)
Scan 1/2- Can phase through his own created statues casually (as well as see through them) (Green Lantern- New Guardians #6)
Scan 1/2- Can also throw these statues as a form of teleportation, using it to ambush Larfleeze. (Green Lantern- New Guardians #8)
Invictus is only defeated by his Orrey being outside of range for his powers to get recharged (as he had put a significant amount of power into his machine) (Green Lantern- New Guardians #12)
Conclusion
Jest Master has supremely effective mind hax, and his planetary range is insane. With his ship's defences, no one can get to him unless they can bypass that hax.
Spaceman X is a energy sponge capable of draining the likes of Green Lantern in about a minute. Adding that with good physical stats and a capability for amping other people makes him a tough costumer to deal with.
The Equaliser can turn a entire group of superpowered individuals into ordinary people: effectively useless. His energy projection is enough that he can defend himself against whole teams of powerhouses without trouble.
Invictus is clearly capable of slapping up herald tiers, and even giving a teambuster a bad beatdown, which makes him pretty damn legit in terms of stats. Busting a planet on panel is pretty sweet as well.