Since she was a child, her own brother eliminated everyone in her family and people she hold dear one by one, right in front of her. She was next too, but acting like a retard, has saved her to survive longer. As her brother, now Tirant King, found it amusing to keep her like a pet. She kept her act for years, even in midst of her torture by evil maids and her own brother. Plus seeing everyone die gruesomely right in front of her. Then suddenly that King wanted to marry her off to that noble family (ML) with ulterior motives to ridicule and ruin that family slowly. But what he doesn't know, is that the ML is a very green flag. Taking care of his wife. (He was the 1st to discover FL to actually be sane, but insist she keeps acting). After many hardship still tight with the king, they must find a way to rebel against him.
What is this? Is this like that story where the princess pretends to be crazy to survive or something?