The power to shift the form of one's body.
The user’s genetic and cellular structure instantaneously rearranges according to mental input from the user. User can impersonate others or enhance one's body to combat, either by turning into animal, monsters or make the body stronger, though it depends on the user's capabilities and limitations.
Users may revert back to original form when unconscious.
Users may require visual or genetic source material for a copy to be made.
May be limited on how long transformation can last.
May be unable to add mass, thus maintaining the physical capabilities of it's original form.
May be unable to return to original form.
May be unable to assume the voice and accent of the person he/she shifts into (rare cases).
Users may be limited to humanoid shapes (human, werebeasts, etc).
Users may retain characteristics of their original form in their new shape (i.e., color scheme, birthmarks, scars, etc.).
May not be able to change genetic coding (meaning blood type, gender and DNA coding), though this does not limit the user from changing into an animal, liquid form, and such.
Staying extended periods in single form may start affecting the users behavior or even make them forget their true self.
Some users may be able to change forms (categorized as humans, cats, weapons, a body of water, etc.), but cannot shape that form into their own customization; instead, it must match their original form's shape.
Such shape that cannot be altered include genetic coding (gender, hair color, blood type), physical appearance (such as a girl cannot change her facial or body structure to resemble another girl's, and while she can change into a cat her fur pattern is based on her own form) and design (such as the girl changing her body into a sword but cannot customize its design for decorative effects).
This may not include the user's age, as it is an aspect of their original form.