MTL - Mission Flow - v2 Chapter 339 answer, reward, song

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Shen Dong's marriage proposal failed, and he was dumped. That night, he was taken away by Chen Yuyan. When he woke up, Shen Dong found Chen Yuyan lying beside him. He was instantly dumbfounded. What made him even more confused was that Chen Yuyan actually said she liked him! And she had liked him for a long time!Chen Yuyan said, “Shen Dong, I want to be with you, but if you don't want to, I won't hold you responsible.”[Ding! The Ultimate Winner System is activated. The host currently has two options regarding the situation at hand.][First option, not taking responsibility for Chen Yuyan and pretending nothing happened, getting a reward of ten million yuan.][Second option, going to the civil affairs bureau with Chen Yuyan today to get married, getting a super gift package reward.]Holy crap! Holy crap!A cheat that could change his life had arrived!

Throughout this current life of mine, I will pay no attention to my past lives, nor will I seek future lives. I wish to live vigorously, to pay back debt of gratitude and fulfill duty to avenge, to defeat valiant heroes from all species, and to proudly laugh at all the Gods and Demons of the Six Path of Reincarnation!