The Tyrant's Guardian is an Evil Witch

A modern woman is reborn as the wicked stepmother in a novel, despised by her stepson, the future tyrant emperor. To survive, she signs a contract to protect him until he reaches adulthood. However, her seemingly cold-hearted son begins to see her as his true mother. Now, she must find a way to survive the political turmoil, protect her family, and escape her dark fate.