Mirarose

Mirarose is a character introduced in the Wandering Witch series. Mirarose was once the princess of a country who was in a secret relationship with a cook. However, after learning she was pregnant with their child, she realized she needed to come clean and told her father, the king, about her affair. Unfortunately, her father was outraged and had her lover executed as punishment. The same was done to her child as soon as it was born. However, Mirarose was actually a powerful witch and, in an act of brutal revenge, she cursed her father, turning him into a giant monster. He then went onto a rampage throughout the country, killing all the inhabitants. Even worse, Mirarose made it so her father was still conscious, forcing him to watch as his monster form killed his people. Mirarose herself took refuge at her family's castle, which she protected with a magic barrier to keep her father and non-magical people out. Wishing to just forget everything, she then proceeded to erase her own memories. However, she left a note for herself which told her who she was and that if she were to leave the country the monster will follow, effectively confining herself to the castle.