Evo is a term for a Caster that can control and influence someone to do, say, or feel whatever they want, like a Siren, can morph into whoever they want, and can borrow the powers of any Caster they touch. Evos are "Evolvers", who are extremely powerful Casters and a type of Dark Caster. Although they aren't as strong and powerful as a Cataclyst, they shouldn't be messed with.
Althea Duchannes was an Evo. When she turned sixteen and was Claimed by the Dark, her mother couldn't stand to send her away and tried to keep her daughter with her, but she was eventually forced to after a girl drowned and a whole town of people got injured, it became obvious that there was no turning back.
John Breed's mother was an Evo who took on human form long enough to conceive a child with all the DNA of a Mortal and a Caster on one side and an Incubus on the other which is how John Breed is able to walk into sunlight, retain his strength without feeding and do things full-blooded Incubuses can't.
- Morphing: They are able to Morph, look and sound like anyone they want. They are only able to mirror human form and become Mortals for short periods of time. When they morph, they can also copy another person's clothing. An Evo could give birth to a Caster-Incubus Hybrid if they become a Mortal long enough to conceive a child with an Incubus or Succubus, with the DNA of a Caster and Mortal on one side, and the DNA of an Incubus on the other.
- Voice Mimicry: They are able to impersonate another's voice if they actually heard it before.
- Mind Control: They are able to control and influence the minds of whoever they want, like a Siren. They are only able to control mortals and weaker Casters, and are unable to control more or equally powerful Casters such as Sirens, Naturals and Cataclysts. Some can control multiple people at the same time, manipulate their bodies and movements without influencing their minds, or producing states of drowsiness in their victims. They can also act on the emotions of people, more easily on mortals. Depending on the Evo, they may have a "trigger" for this power, an object that is the starter of their magic and that makes people around them obey their commands.
- Kelting: Evos, being incredibly powerful Casters, have the ability to speak non-verbally to other Casters who have the same ability.
- Power Borrowing: They are able to borrow the powers of any Caster they touch. Borrowed powers are unstable by nature and the more powerful the Caster they belonged to was, the longer they last.
- Althea Duchannes †
- John Breed's mother †
- Mentioned male Evo
- Indirectly mentioned Evo
- Macon Ravenwood (film only) †