Tears of the Lost
Shapeshifting is a power available only to Chaosites. It is the ability to change ones body at will, and it is an ability that all Chaosites are born with. Shapeshifting is a painful process to go for and is best done in controlled environments, though in emergencies the benefits of shapeshifting almost always out weigh the risks.
All shapeshifters have a Human form and a Demon form, these are the two easiest forms for them to switch between, taking the least amount of time.
It is easiest to cause changes that you have practiced before, or have a model for. Shapeshifters can use there shifts to alter appearance and shape, such as looking like a different person, adding horns or claws etc. More dramatic shifts are possible, such as changing into a wolf, but forms that differ from a humanoid are often very difficult for the shifter to use properly.
Shapeshifters just heal better. While wounds will transfer from form to form and it is impossible to erase an injury, the shapeshifters control of their body greatly increases the healing rate. It also allows rapid bandaging by forcing injuries closed, though this does not eliminate the injury and does take concentration and time.
When a shapeshifter enters an environment they are not able to survive, they will instinctively shift to correct it. Underwater they will grow gills, if they are poisoned the body will automatically attempt to expel or minimize the damage. If the shapeshifters skin is being burnt it will attempt to toughen.