Get branded as a villain Wait for a brutal death? No, To save myself I have to seduce my final hope. I have to seduce The Knight Commander

Van and his friend Magus had reincarnated in another world with magic. Tasked to kill the demon lord, they set forth. Van was granted very rough skills that made life for him in that world a living hell, yet he muscled through. Magus however, was bestowed with unfair skills. Due to some of said skills, he gained a harem, which in time, included the girlfriend Van made in the world. After beating the Demon Lord, and after finding out his girlfriend had been stolen from him, he got very upset and so he went to propose to- *reads script* Uh, WHAT?!

𝐋𝐢𝐥𝐢𝐚𝐧𝐚'𝐬 𝐥𝐢𝐟𝐞 𝐭𝐚𝐤𝐞𝐬 𝐚𝐧 𝐮𝐧𝐞𝐱𝐩𝐞𝐜𝐭𝐞𝐝 𝐭𝐮𝐫𝐧 𝐰𝐡𝐞𝐧 𝐬𝐡𝐞'𝐬 𝐟𝐨𝐫𝐜𝐞𝐝 𝐢𝐧𝐭𝐨 𝐚 𝐦𝐚𝐫𝐫𝐢𝐚𝐠𝐞 𝐰𝐢𝐭𝐡 𝐌𝐚𝐫𝐜𝐞𝐥𝐥𝐨 𝐑𝐮𝐬𝐬𝐨, 𝐛𝐮𝐭 𝐬𝐡𝐞 𝐞𝐧𝐝𝐬 𝐮𝐩 𝐟𝐚𝐥𝐥𝐢𝐧𝐠 𝐟𝐨𝐫 𝐡𝐢𝐬 𝐝𝐚𝐝. I'm in love with him but he's in love with my younger sister and has made that painfully clear to me. "Who are you in love with?" I ask softly, my voice barely above a whisper. "I'm in love with Isabella, your sister. She's the only woman I truly care about," he admits, revealing his feelings for my younger sister after we had just gotten married, it hasn't even been twenty-four hours. "I'll fulfill my role as your husband, but don't expect any love or affection. This marriage is just an agreement between our families, nothing more. Do you understand?" His words are cold, piercing through me like arrows. I fight back the tears threatening to fall and manage to reply, "I understand." But my pain would not last long, not until I meet Mr. Russo, Marcello's father who was that head of the Mafia, a dangerous and powerful man who stole my heart.