Here's the New Chapter 4 review, Jujutsu Kaisen Modulo, (The Boy Who kept Repeating)

Here's the Key Revelations

Chapter 4 deepens the mystery behind a first‑grade student, Masaki, who has been “repeating” the same class for three years. Each year, apparently different children, same height, voice, appearance, emerge with new names and then vanish when promoted. No police involvement, but suspicions of curse user influence arise. 

At the same time, we officially get confirmation of Maru’s alien identity from Usami, who orders that Maru, Yuka, and Tsurugi now form a joint mission team. Maru reveals he is 19 (in Earth years) and hints at alien realm physiology different from humans.

Yuka, via her own investigation at the Takeda residence, discovers something more disturbing: five corpses buried in the yard, suggesting Masaki’s repeating phenomenon is tied to death, illusion, and misuse of cursed energy. The chapter ends on tension, with the implication that the case is far darker than a mere curse or ghostly trick.

Strengths

1. Atmosphere & Horror Elements
   The slow reveal of bodily remains, the uncanny repetition of children with the same traits, and the haunting grief at the heart of Masaki’s curse create a chilling, psychological horror vibe. The blending of grief and curse feels emotionally potent.

2. Character Stakes & Team Dynamics
   The forced teaming of Maru, Yuka, and Tsurugi (with secrets in the mix) gives fertile ground for interpersonal tension. Maru’s alien secret adds tension, both in terms of trust and in narrative weight.

3. Mystery & Layering
   The chapter raises more questions than it answers: how Masaki’s repeating phenomenon works, the role of death and corpses, and how much of it is illusion. That kind of ambiguity keeps readers engaged.

4. Expansion of World & Theme
   Bringing in alien identity, hidden intelligence gathering, and interspecies diplomacy gives a broader scale to what could otherwise be a monster-of-the-week arc. It’s not just about curses but what “truth” means in a world of secrets.

Weaknesses / Challenges

1. Risk of Overcomplication
   With multiple plot threads (alien politics, curses, illusions, mysteries of identity), there’s a danger that the narrative becomes convoluted. If too many threads remain unresolved, pacing or coherence might suffer.

2. Emotional Distance
   Masaki is presented more as a “mystery device” than a fleshed-out, sympathetic character (so far). The emotional weight of his trauma needs more grounding if readers are to fully invest.

3. Pacing & Payoff
   Because much is shrouded, the satisfaction of revelations might lag behind. If the next chapters don’t deliver strong payoffs, the slow build could feel frustrating.

4. Balancing Secrecy & Clarity
   Revealing Maru’s alien origin to the readers but keeping it secret from the team (and perhaps the readers) is tricky. The author must carefully calibrate what the audience knows vs. characters know, to avoid confusion or unintended plot holes.

Themes & Symbolism

• Grief as Curse: The repeating phenomenon is tied to Masaki’s inability to let go of his mother’s death, constructing illusory identities and burying her body himself. Grief becomes literalized as a curse.
• Illusion vs Reality: The use of false identities, hidden bodies, and buried secrets underscores one of JJK’s long-running themes: not everything is what it seems, and perception can be manipulated.
• Trust & Secrets: In the context of Maru’s alien identity, trust among the three protagonists is central. Secrets, both on cosmic/diplomatic and personal levels, become narrative currency.
• Identity & Repetition: The idea of repeating selves raises existential questions: who is the “real” Masaki? Are the duplicates mere constructs? What defines one’s identity in a world of illusions?

What It Suggests for the Arc Ahead

• The Masaki case is likely a foundation for a larger scheme, something bigger is pulling strings behind the scenes (perhaps alien, perhaps curse overlord).
• Maru’s alien background will likely play into the mechanics (why Masaki’s phenomenon is possible) or the secret controllers.
• The team will face moral dilemmas: how much to pursue the truth, and at what cost, not just physical but mental/emotional.
• Expect stronger revelations about the nature of the cursed technique, how far illusions can be pushed, and possibly past links to established lore (maybe tying back to unresolved plotlines).
• The tension in the team (Yuka vs Maru vs Tsurugi) may be exploited, betrayals or fractures are possible if secrets come to light.