Wither

Wither is a rare type of anti-energy, but also the entity, manifestation of death itself.

Wither as an energy
Wither energy does what it sounds like; withers. It can wither away anything that lives and doesn't live, for example, it could dry out a stone building, making it to collapse as if it was centuries old. The energy is black and can come in any form and turns the user's skin white. Problem is, that it's a passive ability. You can't stop emitting it and thus will forever wither whatever you touch.

Wither as an entity
Wither is what comes out, if its user gets consumed by the power entirely. It is for now unknown what this entity is, but it is suspected to be what would be the true Death, as its point of view on the world seems to be that the purpose of life is indeed death. The idea of death being a sentient being has been a troubling question for long, that even Gods do not know.

What is known, is that the power originates from the Tree of Death located in Limbo.