The Ghost

The Ghost is the main antagonist of The Letter. 

Her name is Takako (崇子). She was a Japanese servant of Charlotte Ermengarde. 

Takako found out about Charlotte's infidelity which led her to be raped and tortured, and then framed for witchcraft and the murder of Charlotte's fiancée Eduard. Afterwards the grudge-born ghost Takako haunted her mistress who ends up committing *******. /