I Became the Dark Saintess Fated to Bear the Tyrant!

Our reader is reincarnated as Serena, a saintess in a novel who's destined to be treated like a villainess, give birth to a tyrant, and get executed for it. When the royal family accuses her of being an imposter, she must demonstrate her power as a saintess to survive. But once she does, she's trapp