It is unknown who originally created this magic, but it is believed that vampires had something to do with it. As such, this magic only works during the night and allows the user to be, what appears, immortal. Stories also tell of users of this magic, who were fatally wounded during the day, have burst into flames and permanently died.
By using the caster's magical energy, this magic allows the user to regenerate their body regardless of how mutilated or destroyed their body is. The caster is regenerated as either a shadowy mass or as swirling ash that will reform and solidify.
Dalv, the only known natural user of this magic, has stated that there's no such thing as immortality and has stated that certain magics and magical items seem to do more to him than others.
He does what he can to avoid fighting mages who use Light Magic or Fire Magic, saying that those magics may actually keep him dead as a glancing blow from these magics have left him injured longer than any other magic. It is unknown exactly which magical items counteract this magic, the items are believed to have been lost to history (but not destroyed).
Though never tested, as those who see this magic in action tend to be too stunned to do anything, it is rumored that if you attack while the caster is reforming they will stay dead. It has been confirmed that for a few moments after regenerating the caster's body will be stiff and not move as well it normally would.
Tenjin's synthesized version of this magic is believed to be weaker as the Research and Development Team of Shadow Broker did not fully comprehend this magic and thus only managed to create an imperfect copy. Because of it being believed to be weaker it is also believed that even a glancing blow from Fire or Light Magic would mortally wound, if not kill, Tenjin. This has yet to be proven, however, as Tenjen uses another magic to defend against Fire and Light Magics.