Bastet Curse

"The ancient chronicles speak of a heinous curse. It dooms its victim to turn at the stroke of midnight into a vicious, bloodthirsty beast."

- Gaius to Merlin

The Bastet Curse is an enchantment that dooms its victim to turn into a bloodthirsty Bastet at the stroke of midnight. This curse has no time limit; its victim is forced to kill forevermore.

History
An unknown sorceress placed this curse on Freya after she killed her son in self defense. Because of this, Freya was cast out by the Druids and eventually ended up a prisoner of the bounty hunter Halig.

Freya killed many people under the effects of this curse, including several people in Camelot after Merlin helped her escape captivity. One of her victims was her captor Halig, who cornered her with Arthur and the Knights of Camelot when she tried to flee the city under cover of darkness.

After she attacked Halig, Freya fled and managed to escape with Merlin's help, but not before being mortally wounded by Arthur. She later died of her injuries on the shores of the Lake of Avalon (The Lady of the Lake).

Trivia

 * Any injuries the victim receives as a Bastet will transfer to their human body when they change back (The Lady of the Lake).
 * Though victims of this curse are unable to control their desire to kill while in Bastet form, Freya was able to resist attacking Merlin. It is unknown if her love for him allowed her to resist the curse, or if she had merely met the curse's requirement for that night by killing Halig (The Lady of the Lake).