Unnatural World Wiki

"We cut him, but he's not getting cut!?"
"No! We cut him! That's for sure! But this monster... regenerates the moment we cut him!"
"He won't die if we cut off his head. He regenerates so fast its impossible to slice up his body."
― Demon Slayers in regards to Muzan Kibutsuji's (Kimetsu no Yaiba) instantaneous regeneration

Healing Factor is the ability to recover from bodily injuries or disease at a supernatural rate.


Users possess a regenerative healing factor, meaning that they can rapidly heal and get restored back to their optimal and full health/state at an extremely fast rate. Unlike Healing, regeneration/healing factor is a process that happens unconsciously without the need of activation, resulting in a constant state of optimal health. Regeneration is a process that occurs in all biological entities, but a regenerative healing factor is much more efficient, seamless and powerful. So much so that users can recreate lost or damaged tissues, organs and limbs, sometimes slowing, or even stopping aging, something natural regeneration can never accomplish (or does so extremely slowly). The rate and amount of healing vary widely (see Levels of Regeneration); some can regrow missing limbs, others must put the limb back in place for rapid regeneration. The user is generally in very good physical shape, as their bodies are constantly reverting to a healthy state, granting them nigh-inexhaustible stamina and vitality.

The regeneration process also increases the speed of processes the body uses in the healing such as endorphin production to mitigate pain reducing the amount of time and severity the subject feels discomfort leading to an increased pain threshold. Other processes included are the production of adrenaline and the fight or flight response which are greatly extended by the increased recovery leading to increased physical performance as the subject gains elevated strength and energy while also able to push their bodies harder due to decreased sensation of pain.

At higher levels, a user can regenerate not just their cellular tissues, but also their DNA, undoing genetic mutations and breakdown, as well as maintaining one's youth by extending telomeres. This also gives them immunity to diseases and infections, undoing any unwanted symptoms, as well as providing a form of self-sustenance, foregoing the needs for oxygen and food intake. If advanced enough, the ability will cause the body to cease aging as the cells are regenerating and dying in equilibrium, granting immortality.


  • Acquired Immunity
  • Contaminant Immunity
  • Disease Immunity
  • Intelligent Regeneration
  • Injury Immunity
  • Longevity or Immortality
  • Disease Immunity
  • Healing - Self
  • Limb Regrowth
  • Limb Reattachment
    • Head Reattachment
  • Mental Regeneration
  • Nerve Regeneration
  • Organic Preservation
  • Pain Suppression
  • Regenerative Durability
  • Regrowth
  • Reforming
  • Self-Sustenance
  • Sleep Suppression
  • Thermal Resistance


  • Level I
    • Healing may be unreliable, either failing or have a limit on how many times it can be used.
    • May come at a cost, such as accelerating cellular division and aging to close up the wound.
    • May require a certain condition to activate regeneration, such as the consumption of blood.
    • Regeneration may be limited to a certain part of the body, instead of the whole.
  • Level II
    • Minor wounds such as cuts, bruises, and light burns heal faster than normal.
    • Recovering from minor to moderate blood loss.
    • Critical wounds such as lost limbs, damaged nerves, and internal organs cannot be regenerated, as wounds would simply close up faster and lost organs remain lost.
    • Cells that are fatally damaged, such as by burning, cannot be regenerated, resulting in permanent scarring.
  • Level III
    • External wounds, including fractured bones and deeper burns, may heal at an accelerated rate, disregarding severity.
    • Cellular and genetic damage is reduced, greatly extending the user's lifespan.
    • Lost limbs may be regenerated quickly or can be reattached.
    • Can survive severe blood loss.
    • Minor damaged internal organs may heal, but more severity may be beyond repair and may take more time to heal.
    • Nerves may remain damaged.
    • Tumorous cells may actually be multiplied via regeneration as they are considered living cells.
  • Level IV
    • Minor to moderate wounds heal near-instantaneously, appearing as though they never happened, with more severe injury taking minutes or hours to heal.
    • Lost limbs, internal organs and damaged nerves will be completely regenerated.
    • Cellular senescence is drastically reduced, if not completely halted, granting decelerated aging/eternal youth.
    • Critically and fatally damaged cells can regenerate, preventing scars.
    • A user can regenerate as long as the head/brain is damaged to no more than a certain level.
    • Disease Immunity
    • A user is near-completely unaffected by toxin or drugs.
    • Destruction of the head is one of the few sure methods to ensure the use of this level's death.
    • Healing strength may be so powerful, the blood is enriched with healing powers that can be used to heal others.
    • Tumorous cells may actually be multiplied via regeneration as they are considered living cells.
  • Level V
    • Cellular regeneration and rejuvenation would be so powerful, the user would be close to true immortality.
    • Brain cells and nerves can be completely repaired, to the point of keeping the mind intact.
    • Decapitation can be reduced in effectiveness as the user can reattach their heads and seal the cut.
    • Contaminant Immunity
    • A user is forever in their optimal health and physical prime.
    • Tumorous cells will be healed to the point of returning to their optimal, healthy form.
    • The only way to inflict long term exhaustion and injury on the user is to use attacks faster than the speed of regeneration at a repeated rate.
  • Level VI
    • A user may regenerate all bodily damages on an ultimate scale.
    • Decapitation would be pointless as a user can regenerate a head, or the head can regenerate a whole new body.
    • Impossible to exhaust or permanently injure, regardless of attack speed.
    • Removal of soul or temporal erasure are the only methods of killing the user.
  • Level VII
    • A user can regenerate anything/everything on a near absolute level.
    • An only possible method to truly kill the immortal is to first find a method to negate regeneration.
  • Type VIII
    • A user may regenerate even if their body and soul are completely destroyed.
    • Complete destruction results in complete restoration.
    • Physical, mental, spiritual, temporal, and conceptual states will restore to full without fail.
    • Cannot be nullified/erased/removed in any way.