Satoru believes he is the strongest person in existence, and he is most likely correct. He confidently states that he could defeat Sukuna even if he regained all his fingers, and that is not just an empty boast. He has an immense amount of cursed energy, and never seems to get tired. His Limitless Technique is completely overpowered, as it not only allows him to essentially avoid all damage, but also allows him to create powerful singularities that can destroy anything they touch.
During his fight with Jogo, Satoru never once seemed concerned and ended the fight with ease after trapping Jogo in his Domain Expansion: Unlimited Void. Later, he almost killed Hanami with his Limitless: Hollow Purple Technique, and likely would have killed the Curse if he had landed a direct hit. Satoru is easily the most powerful character in the series, and arguably one of the strongest in any anime.
The undisputed King of Curses, Sukuna is so powerful that a single one of his fingers is enough to create a special grade Curse. He easily defeated the Finger Bearer in the juvenile detention center, and can literally tear opponents apart with his Dismantle Technique, such as when he slashed Mahito after the Curse tried too many times to touch Sukuna's soul.
His Domain Expansion: Malevolent Shrine, allows him to attack anything within 200 meters at will, and if that's not enough, he is incredibly cunning and patient. Sukuna is willing to wait for the perfect chance to strike, and once he does, he hardly ever misses.
Even though Hanami does not possess as much cursed energy as Jogo or Mahito, Satoru claims Hanami is the more threatening Curse. Hanami is unbelievably durable and able to brush off most attacks from weapons and techniques with ease. Additionally, Hanami's ability to suck the lifeforce from the surrounding environment means she can sustain damage that would disable most sorcerers or Curses.
On several occasions, Hanami has taken Satoru by surprise, indicating that she is able to mask her presence. Also, Hanami's Disaster Plants Technique is amazingly versatile and can be used to alter the environment, distract and weaken opponents, and boost her movement speed.
Despite not being able to defeat Satoru, Jogo is no slouch. He possesses as much cursed energy as eight to nine of Sukuna's fingers, which alone makes him an incredibly powerful Curse. Jogo has an arsenal of fire and lava attacks at his disposal that are capable of incinerating people within seconds.
His Disaster Flames Technique creates small volcanoes that erupt and destroy anything they touch, while his Ember Insects grant him the ability to attack his opponent accurately from long range. Any average sorcerer trapped inside his Domain Expansion: Coffin of the Iron Mountain would be instantly engulfed in flames, and while it didn't work on Satoru, Jogo should not be taken lightly.
Although Mahito is a relatively young Curse, he is already terrifyingly powerful. In addition to being quick on his feet, he is also exceedingly cunning and creative. He managed to get the better of Kento during their one-on-one duel in the sewers, and he likely would have defeated Yuji and Kento during their later fight, if not for the intervention of Sukuna.
His Idle Transfiguration Technique gives him the ability to reshape souls. In addition to being hideous, it's also extremely powerful and has limitless possibilities, as he can use it to reshape his body at will, heal himself, or disfigure his opponents. While he has yet to master his Domain Expansion: Self-Embodiment of Perfection, once he does, he will become even more dangerous.
It's easy to look at Kento and assume that he is just a mild-mannered salaryman, but looks can be deceiving. Behind his neat appearance and monotone voice is a cold-blooded fighter with years of experience underneath his belt. He has great control over his cursed energy, and his two Binding Vows, Overtime and Revealing One's Hand, allow him to access even more power, so much that he is able to coat his entire body in cursed energy.
Before Yuji, Kento held the record for the most consecutive uses of Black Flash, but that is not even his go-to technique. His Ratio Technique is his signature move and allows him to exploit a weak point anywhere he chooses on his opponent's body. With so many tricks up his sleeve, Kento is a truly powerful sorcerer.
Based on his physical figure alone, it's obvious that Aoi is fantastically strong. His muscles are covered in muscles, and with a single punch, he sent Yuji flying dozens of feet and through a fully-grown tree. He admits that he managed to defeat five grade 1 Curses and one special grade Curse during a single night, yet he is not overly confidant or cocky.
Aoi is not only physically strong but also incredibly intelligent, and he is able to analyze and predict his opponent's moves within seconds. While his Boogie Woogie technique does not have any innate offensive or defensive capabilities, his skill allows him to use the technique to completely take over a battle and use the environment to his advantage.
Prior to becoming Sukuna's vessel, Yuji was already a physical freak of nature. He is naturally strong, agile, and fast, as seen by his ability to fight a high-level Curse in the first episode, despite not having any cursed energy at the time. After he learns to harness cursed energy after training with Satoru, Yuji's power level increases even further.
His Divergent Fist Technique packs a serious punch, but his ultimate technique is Black Flash. Black Flash is 2.5 times more powerful than a normal hit and capable of damaging even innately powerful special grade curses, like Hanami. Currently, Yuji cannot use Black Flash at will, but if he learns how to do so, his power ceiling is immeasurable.
Megumi inherited the rare and powerful Ten Shadows Technique from the Zenin family, which on its own makes him a powerful soldier. In addition to his natural talent, Megumi is also a skilled martial artist who can hold his own in a straight-up brawl. His greatest weakness has been his lack of drive and creativity, something that Satoru has often criticized him for during their training sessions.
Once Megumi lets go of his mental restraints, he becomes a truly powerful sorcerer. In his fight against the Finger Bearer under Yasohachi Bridge, Megumi was able to unleash his Domain Expansion: Shadow Garden for the first time, even though he was heavily damaged and defeated a powerful Curse that should have been way above his level.
What makes Nobara so powerful is not necessarily her technique, but her fearlessness in battle. She is always calm under pressure, and never allows herself to panic or slip into despair. During the Goodwill event, she handily defeated the grade 2 sorcerer, Momo Nishimiya, despite only being ranked as a grade 3 sorcerer at the time.
Later, when she and Yuji fought Kechizu and Eso, Nobara managed to keep her cool, even when she was poisoned by their Rot Technique: Decay. Nobara's Straw Doll Technique has the potential to flip any fight in her favor, and she is dangerous not only at close distance but also at long range. Her power level is worthy of a grade 1 sorcerer, and she certainly has more room to grow.