Tasha is a famous witch. She who rarely shares too much about her backstory or how it is that she first came to be a Dreadlord in Ravenloft.
What is known is that it has to deal with her recent publishing of a book that contained spells to summon and bind celestials.

Her Domain was visited by the party in Session 3 and appears as a nostalgic take on suburbia with influences of Stephen King, 90s-2000s teen horror tropes. It’s all rather strange.

She appears to be a young women with wavey black hair, a tattoo of what appears to be a rune under her right eye and wears a witches hat and black dress.

Her right arm was lost to ‘pay’ for the party’s travel on The Mourning Rail and replaced with one made of gleaming gold metal.

She rather prefers if you don’t mention it.. nor the fact that since travelling to Cavitius the necrotic energy has really done a number on her, her skin blackening as her life force is slowly drained away from the sheer amount of necrotic radiation leaking in from the Plane of Negative Energy.

Thankfully she was saved from death by Koran on the promise that she would KILL Strahd von Zarovich in return for her dragging her though Cavitius in his misguided attempt to take over Vecna’s Domain of Dread.