Locked by the Red String

A powerful heir is poisoned by a rare dragon venom, and only a woman born with a blood phoenix mark on her neck can cure him, at the cost of irreversible harm to her. Unwilling to hurt an innocent, he decides to give up treatment. But when his brother dies and the family bloodline falls on his shoulders, his mother brings his wife back home. No one knows that this gentle, quiet wife is the one and only phoenix born, the only person who can save his life!