Su-In’s Power & Relationship With Heidi In ‘Parasyte: The Grey’

Netflix’s latest series, Parasyte: The Grey, an adaptation of the Parasyte manga and anime, is airing now. As a fan of the anime, I must say they’ve done a pretty good job making this series a type of spinoff from the original material. To be fair, the anime was pretty well detailed about the Parasites, and it only makes sense why Netflix decided to play it safe by coming up with an original story set in the same universe.


Spoilers Ahead 

What Is Su-In?

The protagonist of this adaptation, Jeong Su-in, is a young woman living in Namil-gun, Korea. Growing up with an abusive father, her mother walked out on Su-in and started another family of her own. After her mother’s exit, Su-in was compelled to have her father arrested because of the persisting abuse. Following this incident, Su-in was ostracized by everyone in society for complaining against her own father. Su-in’s intentions to reunite with her mother were also shot down by her mother, who preferred not to be contacted again. Su-in grew into a loner without friends or family. In fact, the only person she considers close to her is Officer Cheol Min, who saved her from her father. Cheol Min empathized with the girl and became a father figure for her. 


As an adult, Su-in works as a receptionist at a local supermarket. On one fateful occasion, while at work, Su-in crosses paths with a psychopath. This man initiates an unprovoked argument when she politely asks him to get some of his items billed elsewhere. Seeing that people are protesting against the ruckus he is creating, the man walks away and waits for Su-in to get off her shift. On her way back home, he apprehends her and then stabs her multiple times. Fatally injured, Su-in crawls away from the man. Meanwhile, a Parasite larva nearby makes its way towards Su-in, merges with her brain, and kills the man pursuing Su-in, protecting her from an imminent death. 

Su-in’s past as a lonely, abandoned child plays an important role in the story. She is initially depicted as a weakling but starts to become a person who doesn’t even fear death. She takes accountability for everything that happens around her, even though she sometimes antagonizes herself. But then, call it fate when Su-in, a loner, finds herself a permanent companion who always has her back. 


What Are Su-In’s Powers?

The Parasite, Heidi, occupies a part of Su-in’s brain after the incident. Because of Su-in’s fatal injuries, Heidi had to heal her injuries before they could merge with Su-in’s brain. As a result, Heidi runs out of the energy she requires to merge with the brain completely. Even as a mutant, Su-in shows the characteristics of a human. Even her X-Ray scan shows that she is a human.

As a Human-Parasite hybrid, Heidi is kind of a split identity for Su-in. When Heidi takes over, Su-in is unconscious; however, Heidi is constantly aware and can take control at will. Parasites, by instinct, are supposed to be simple creatures who survive by eating humans, but Heidi is different. Their relationship with Su-in is pretty much symbiotic. Even Heidi’s dietary needs are fulfilled by Su-in’s food intake. 


As a mutant, Su-in can harness the power of a Parasite when Heidi takes over. Unlike other Parasites, who show their true forms by disfiguring the human head and transforming into grotesque monsters with multiple tentacles, Su-in’s Parasite mode is slightly different. Heidi only resides on the right side of her brain, which is why only a part of Su-in’s head is transformed into a parasite, which hardly affects Su-in’s human appearance. Because of the same reasons, Heidi only possesses one tentacle, which they use for combat. Heidi can morph the integrity of their tentacle however they wish to. At one point, they even lengthened it to a hundred meters or so. This tentacle bears sharp blades that can slice even metal with ease. Moreover, as a part of Heidi’s Parasite body, the tentacle can perform high-speed maneuvers during combat and even lift heavy objects. 

Su-in also possesses super-healing abilities because of Heidi’s presence. This can be seen in the instance when Heidi completely heals Su-in’s stab wounds in the beginning. When in mutant mode, Su-in also experiences enhanced agility and strength. Su-in can also leap higher than an average human. 


What Is The Symbolism Behind Su-In’s Relationship With Heidi?

When we’re in an emotional conundrum, it helps to have an outside voice to help us put our disorganized thoughts into place and to remind us of objective reality. For Su-in, Heidi ends up becoming that outside voice. In an extra-terrestrial life form, Su-in finds company that she doesn’t initially embrace. When Heidi shows her real form to Su-in through a video, Su-in is horrified to see her morphed face. However, through the events of the series, Su-in learns to rely on Heidi through their misadventures. 

Su-in and Heidi’s relationship isn’t one-sided. In the animal kingdom, this kind of relationship is called a mutualist symbiotic relationship, often seen between hermit crabs and sea anemones. It is surely quite fascinating that even simpler beings lacking advanced nervous systems can enter into agreements with other organisms, which benefits both of them. Similarly, Su-in and Heidi’s bond symbolizes the interconnectedness of the flora and fauna in this world as a mutually beneficial ecosystem. In hindsight, their relationship even highlights the human condition in the present day and age. Human greed and our expansionist tendencies have already disrupted the way nature works. But Heidi and Su-in’s bond is a subtle reminder of how stability can only be achieved when all beings respect nature. 


The relationship between the two also transcends more than just their physical requirements. As a parasite, Heidi was born with only one purpose: to eat humans. However, they failed to follow that directive the moment they failed to take over Su-in’s brain completely. After this, Heidi ensures her survival, which becomes her only purpose. Unlike humans, Heidi is a simple-minded creature and is rather short-sighted, even though she is extremely intelligent. 

Heidi represents humanity as a hunter-gatherer, starting out as an organism that struggles to fulfill its physiological needs. However, as Heidi starts to co-exist with Su-in, a human in a world of multi-layered conflicts, they experience fear, a complex emotion that evolves from their need to survive. Heidi eventually starts observing Su-in’s own battle with depression and her fear of abandonment. That is when Heidi fathoms the concept of human suffering. Soon after this, they begin to question their own existence. Heidi contemplates their purpose in this world as a sentient and intelligent being, which is helped by their co-existence with Su-in. Heidi could kill anyone they wish to, but Su-in’s own stance against murder makes them realize the significance of subjective morality. 


In a nutshell, Su-in being a mutant makes us contemplate what makes us human in an ecosystem. It shows how we’re co-dependent beings, relying on nature around us. Moreover, Heidi’s own journey talks about human evolution from mindless creatures to social beings with a conscience and morals.

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Shrey Ashley Philip
Shrey Ashley Philip
A teacher, photographer, linguist, and songwriter, Shrey started out as a Biotechnology graduate, but shifted to studying Japanese. Now he talks about movies, advocates for ADHD awareness, and embraces Albert Camus.

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