"I used to make fun of Green Lantern for being vulnerable to the colour yellow! Then I choked on my orange juice one morning and nearly suffocated."
― T-Rex, Dinosaur Comics
The circumstance in which the user has a supernatural weakness when in contact with a certain object, occurring event, or emotion. Opposite to Affinity.
Users become weaker when they come in contact with a certain object, event, or emotion. It is also possible to weaken or nullify existing powers as well. Long-term exposure to the aversion may result in fatal bodily conditions (e.g: Cancer), or even death.
Elemental Aversion - become weaker when in contact with a certain elemental force.
Environmental Aversion: become weaker when in certain landscapes.
Empathic Aversion - become weaker when feeling (or in contact with someone's feeling) a certain emotion.
Life Aversion: become weaker with more living things near.
As displayed here with Son Goku (Dragon Ball), a Saiyan's tail is so sensitive to touch that if grabbed, the Saiyan in question will become paralyzed and have their powers drained.
Roy Mustang's (Fullmetal Alchemist) Flame Alchemy becomes utterly useless when he's wet.
While Utsuro (Gintama) feeds off the Altana of his birthplace Earth to live, he cannot intake the Altana of any other planet as it is effectively poisonous to him, as Umibozu caused his body fatal damage with Kouan's crystalized Altana.
While Kouka (Gintama) feeds off the Altana of her birthplace Kouan to live, she cannot intake the Altana of any other planet as it is effectively poisonous to her, as she died when she immigrated to Rakuyo, far away from Kouan.
Devil Fruit Eaters (One Piece) such as Monkey D. Luffy and Brook are unable to swim and become powerless and immobilized if over half of their bodies is submerged in water.
When DIO Brando (JoJo's Bizarre Adventure) was turned into a vampire, only sunlight or Ripple/Hamon users could truly kill him.
Pillar Men (JoJo's Bizarre Adventure Part II Battle Tendency) are vulnerable to the rays of the Sun and to the Ripple/Hamon.