Dressed as a Vicious Young Master, the Yandere Prince Insists on Me?

[Two male protagonists + time travel + magical medicine + yandere prince + redemption] After the sudden death of medical doctor Lu Ming, he transformed into the empire's notorious vicious young master. The original owner was uneducated, his parents were disappointed, and his brother even prepared to send him away for marriage. Facing a magical world where there is no medicine and civilians can only wait to die, Lu Ming returns to his old business: transforming healing techniques, cracking plagues, and establishing civilian rescue homes. But he saved more and more people, and the mysterious pen pal who only communicated in letters also came to visit. "Lu Ming, the entire empire belongs to me, and I only belong to you."