The Shape-shifting rune allows the person Marked with it to take someone else's form.
Known instances of use
- Lydia Branwell into Valentine Morgenstern
- Valentine Morgenstern into Michael Wayland
- Clary Fairchild into Victor Aldertree
- Isabelle Lightwood into Mark
- Raj into Alec Lightwood (drawn by Isabelle; deactivated by Aldertree)
- Jace Wayland into Simon Lewis
- Jace Wayland into Clary Fairchild
- It seems that when the wearer—if he/she applied the rune on him/herself—is weakened, the rune may fail and the user's true form may be revealed.