Zombie

Zombie (ゾンビ), also referred to as the Zombie Girl or the Voodoo Zombie is a minor character introduced in Shinyaku Toaru Majutsu no Index. She is one of the Magic Gods that resided in the Hidden World as part of the true Gremlin, and through her theory that allowed her fellow Magic Gods to step into the world of humans without destroying it after Aleister Crowley breached their world. However, it is her power that eventually led to her and her fellow Magic God's downfall, later being defeated and shown before the eyes of her fellow Magic Gods.

Etymology
The idea and word "" originated in Voudon beliefs in the Caribbean, though the etymological roots date back to West Africa. It referred to those enslaved by sorcerers who have not allowed them a peaceful death or have put them in trance to make them think they are dead. In recent times, it is more commonly used to refer to a type of undead creature.

Appearance
Zombie appears as a girl whose entire body is covered in stitches.

Background
Zombie is a Magic God, and along with others, has resided in the Hidden World, separate from humanity.

According to Nephthys, Zombie has a background of actively drawing in a great number of cultures. Because of this she has an affinity for almost anything. It is this affinity of hers that allowed her to create a theory that allowed the other Magic Gods to step into the world without destroying it.

Magic God Othinus Arc
She is one of the other Magic Gods mentioned briefly residing in the Hidden World.

When Aleister Crowley breached the Hidden World, his purpose was to acquire data on the Magic God's base parameters, which would later allow him to forcibly swap Zombie's spell, the spell that would infinitely divide a Magic God's existence, for one would allow him to make a Magic God mortal.

St. Germain Arc
Following the loss of their Hidden World, Zombie devises and implements a spell to allow her fellow Magic Gods to enter the world without destroying it. Somehow she later appears in Academy City on her own without the knowledge of the High Priest's group that have arrived separately from her. There, she is defeated through unknown means, likely by either Aleister or Kihara Noukan. Her body is then wrapped in barbwire and nailed with tungsten spikes on a steel beam cross resembling the Rose Cross.

After the defeat of St. Germain, while the High Priest's group communicate with Aleister, who has substituted Zombie's spell with his own, her body is catapulted by Noukan towards them, showing them their hubris in underestimating Aleister Crowley.

Abilities
She is a Magic God that is so powerful that her mere presence in the world may destroy it. Due to her drawing many different cultures she was able to formulate a spell that would allow a Magic God to walk in the world without destroying it, which works by infinitely dividing their power in order to deliberately weaken themselves. According to Aleister Crowley, this technique is merely tricking the world to contain a Magic God to exist by eternally layering their existences in a form that is barely small enough for it.

Even though this spell weakens a Magic God, it essentially makes them unkillable as their existences are eternally layered, preventing from truly getting killed unless all of the infinite layers of their existences are killed.