IMPORTANT: If you don't want spoilers about the character or their abilities, skip this.
What to expect: I'm not really a writer — I was just bored, had time, and what I hope was a good idea. So I'll probably make mistakes throughout the story, and I'd really appreciate it if you point them out. I love comments, so feel free to leave them often (•؎ •)
About the protagonist: although he'll be strong (like everyone, I enjoy OP characters), I try to make it feel natural as much as possible. He also has quite a few personality flaws and will make dumb mistakes throughout the story — I really want him to feel as natural as possible.
If you're expecting a completely perfect protagonist with no personality flaws and a thousand powers, this probably isn't the story for you (ᴗ_ ᴗ.)
As for romance, I haven't decided anything yet, but if it does happen there definitely WON'T be a harem — I really dislike harems. Suggestions are welcome. Without further rambling, here's the MC info ദ്ദി(◝ ⩊ ◜).ᐟ
━═━═━═━═━═━═━═━═━
Name: Kagami Rei
Age: 15 years old
Personality:
Rei is an extremely introverted and socially awkward person — the kind who overthinks how much he needs to say in a conversation to keep it from feeling uncomfortable. He is quiet by nature, not out of shyness but simply because he doesn't see the need to fill the silence.
However, when alone or comfortable, he shows a more childlike and playful side — he makes quiet comments to himself, gets entertained by small details, and has a methodical and slightly obsessive curiosity about understanding how things work. He is particularly uncomfortable around very extroverted people, though thanks to Itadori and Gojo that discomfort gradually fades.
He tends to make important decisions without drama and holds them without needing anyone's validation.
Appearance:
(Appearance doesn't affect the story — feel free to imagine him however you like)
Rei is a young man with messy, slightly unkempt black hair. He has a pale, almost sickly complexion that has improved over time, with faint dark circles under his eyes. While not unattractive, he would be described as cute rather than handsome. He has a slim build — he was mildly malnourished before, but has gained weight over time.
His Jujutsu uniform is similar to the standard one with slight modifications: the trousers are somewhat loose and the top has the sleeves cut at elbow length.
Cursed Energy:
Rei's cursed energy is light purple in color, slightly darker than Yuta's pink energy — visually distinct from normal cursed energy. The quantity is abnormally high, and combined with his enormous output it appears almost infinite, though his control is not as refined as other sorcerers.
Innate Cursed Technique:
Paradox (逆説 / Gyakusetsu)
Rei's innate technique allows him to create paradoxes that initially only affect himself. In the early stages he is incapable of creating paradoxes that directly affect the environment or others — all manifestations of the technique originate from his own body. With training and time, the reach of the technique gradually expands.
Extension Techniques:
Nisoku (二足) — "Two Steps"
Movement / Combat base
Rei's fundamental technique. Creates a paradox of position — his body exists simultaneously at two points in space. In practice it manifests in two forms depending on control:
Basic form: Short-distance teleportation. Rei eliminates the path between two points, appearing directly at the destination without having traveled. It is not speed — he didn't move conventionally, he simply was never still in the first place.
Advanced form: The movement that never happened. The action ignores distance and movement entirely, existing directly at the endpoint while bypassing barriers or shields — as demonstrated against Gojo's Infinity. Infinity cannot process something that never traveled.
Limitation: In its initial form the movement is not instantaneous — Rei uses it at short distances because it is as though he is actually covering those distances, just with the physical process of moving omitted and the final result delivered. Physical attacks are equally limited by the same principle: if something is too far from Rei, no matter how hard he tries to hit, the blow will never reach its destination.
Kaimetsu (壊滅) — "Devastation"
Offensive — Paradox of cause and effect
Rei creates a paradox in the cause-and-effect relationship of an impact. The damage exists before the blow lands, during, and after — the logical proportion between applied force and result breaks down completely. A blow that should produce X damage produces an impossible multiple of that damage because cause and effect no longer have a coherent relationship.
Visually: the impact occurs at three simultaneous moments — past, present and future. The enemy receives the same blow three times in distinct instants that coexist.
As this technique develops, the multiplier can stack as many times as Rei's body can withstand.
Limitation: While it doesn't consume much cursed energy, the body must be sufficiently reinforced to withstand the multiplier. In early stages Rei cannot control the damage multiplier well — the technique is powerful but imprecise without perfected cursed energy control.
Kyozetsu (拒絶) — "Rejection"
Defensive — Paradox of existence
Rei applies a paradox directly to an incoming attack — the blow simultaneously exists and does not exist until the moment of impact. Reality cannot resolve which of the two states is true, and while it cannot, the attack cannot complete. In practice, physical and cursed energy attacks have a probability of simply not occurring upon contact with his body. In other words: it leaves the cause and nullifies the effect.
It is not a shield or a barrier — reality simply doubts whether the attack happened or not.
Limitation: Not absolute — it is probabilistic. Against very powerful attacks or high concentrations of cursed energy, the paradox collapses and the attack passes through. Requires active concentration from Rei to maintain.
Sokudo (速度) — "Speed"
Movement / Offensive — Paradox of relative time
Rei creates a paradox of time — his body exists simultaneously in the current instant and the next one, collapsing the time between them. The perceived result is apparently impossible speed, but technically Rei didn't move faster — he eliminated the time it should have taken him to move.
Unlike Nisoku, there is continuity of movement here — Rei moves, but the instants between each step of the movement simply don't occur. The visual result is that he appears to move at a speed that corresponds to no normal human or sorcerer.
Limitation: Cannot easily be combined with Nisoku in early stages — using both simultaneously creates a paradox overload Rei cannot yet handle. Energy cost is proportional to duration.
Reverse Cursed Technique:
Rei's reverse cursed technique generates positive energy that can be used for healing. Due to the nature of Paradox, when Rei heals himself he can amplify the reverse technique with his innate technique — simultaneously declaring that the wound exists and does not exist. The reverse technique heals what exists, and Paradox denies it ever existed. The result is a healing that not only regenerates the damage but erases it retroactively.
When healing others this amplification is unavailable — he can only apply the standard reverse technique, which is slower and more costly.
Derived Techniques:
Absolute (絶対 / Zettai)
Derived ability from applying reverse technique to Paradox
If Paradox creates uncertainty — things that simultaneously exist and don't exist — Absolute does the opposite: it imposes an irrefutable certainty onto reality.
Visually it is almost impossible to describe because it has no form. There is no flash, no explosion, no projectile. It simply happens — and when it happens, reality has no way to deny it.
In practical terms: Rei declares that something is absolutely certain, and reality accepts it without possibility of contradiction. An attack declared as certain cannot be blocked, redirected, absorbed or denied by any technique — because its existence is an irrefutable truth, not a physical event that can be intercepted.
The technique does not damage directly in the conventional sense. What it does is declare the result as an accomplished fact. The damage already happened — reality is simply acknowledging it.
Limitation: Declaring something as absolute truth requires Rei to fully believe it himself — any internal doubt collapses the technique.
Maximum Technique:
Aporia (アポリア)
The most powerful technique in Rei's arsenal. Born from simultaneously combining Paradox and Absolute — a tautological paradox: something that is irrefutably true and impossibly contradictory at the same time.
Paradox declares that the target simultaneously exists and does not exist.
Absolute declares that both truths are irrefutable.
Reality cannot resolve that contradiction.
The target is trapped in a state of existential paradox — unable to act, use techniques, or move, because to do anything it first needs to exist with certainty, and that certainty is being permanently contradicted. Against targets with little cursed energy the collapse is immediate and lethal. Against powerful targets it paralyzes them for the duration of the technique.
Outside the domain expansion, Aporia manifests as an attack similar in nature to Gojo's Purple or Yuta's Pure Love — visible, physical, and capable of being dodged or neutralized. Inside Rei's domain expansion, it changes entirely: the attack can come from any direction, at any moment, in complete silence. There is no warning and no visible form.
Limitation: Requires complete mastery of both Paradox and Absolute simultaneously. The mental stability to sustain two contradictory absolute truths without one's own mind collapsing is the greatest obstacle. Outside the domain expansion the attack can be avoided or neutralized.
Domain Expansion:
Ijou (異常) — "Anomaly"
Rei opens a domain where reality constantly and involuntarily contradicts itself. It has no rule imposed on the enemy — it is simply a space where nothing exists with certainty. Everything is in a permanent state of simultaneously being and not being.
The enemy receives no direct damage, but their body, mind and cursed techniques collapse trying to process the impossible. Rei is the only exception because he does not try to resolve the contradictions — he simply inhabits them. As such, Rei's domain has no guaranteed lethal hit.
In the hypothetical case that an enemy were capable of processing the anomalies, they could move within Rei's domain and even fight — but the only ones likely capable of this feat would be Mahoraga through its adaptation and Gojo Satoru through his Six Eyes.
━═━═━═━═━═━═━═━═━
That's all for now — if you have any ideas I could implement or suggestions for the story, I'm all ears. Or rather, all eyes.