Reiko Tamura

The real name of the person whose body was taken over by the parasite is Ryoko Tamiya (or Ryouko Tamiya). ✅ In the beginning, like all parasites, she ate human flesh—it's their natural instinct: to devour their own species from the body they've taken over. But Reiko was different: she studied and discovered that she could live on normal human food, absorbing nutrients from the body she inhabited. After becoming pregnant and beginning to feel something akin to maternal love, she stopped eating people altogether and began to eat like anyone else: regular meals, vegetables, animal meat, etc.—and proved that she didn't need to kill to survive. Appearance
Initially: shoulder-length light brown hair, attentive brown eyes, slender and elegant build. Later, its appearance changes: long black hair, thinner face, lighter skin; wears formal clothes and maintains a calm and calculating expression. As a parasite, it can alter its face and upper body at will.
⚡ Powers
It can deform and transform its head and limbs into blades, tentacles, or harden cells for defense and attack. It detects the presence of other parasites from a distance. Extremely intelligent: it creates complex strategies, tests the limits of its own body, and defeats stronger enemies through reasoning. It was capable of doing things that no other parasite could, such as temporarily separating parts of its organism.
What does he/she work on/do?
She infiltrates the organization as a math teacher, but her true objective is to study: she wants to understand the origin, purpose, and biology of parasites, as well as compare them to humans. Later, she acts as an advisor to a group of parasites, but remains focused on observing and experimenting—even having a human child as part of her studies.