Fate Online: Shadow - Chapter 385 - So Suspicious.

The dark BOSS, who had the fortune of becoming Earth’s last living human, brought with him his loyal, second last human to die, little brother to be reborn.

[Main Plot Completed]A love doomed from the start, a lost cause, a losing battle—and yet, neither hearts are willing to let go until the very end.-----Arlan Cromwell, the epitome of the perfect Crown Prince. All he wants is to live a normal life of a human but the life of a dragon is anything but normal. He has but one goal—to find his runaway betrothed and behead her. What happens when he discovers that the woman who has snagged his heart is the one he vowed to kill?Oriana, a Black Witch, disguising herself as a man, has spent her entire life on the run without knowing what she is running away from. When the mysteries of her past slowly catch up to her, she has no one to turn to…except Arlan. But when she learns that the man she has given her heart to is the same man who wants to kill her, how can she accept the cruel card life dealt her?Two people with secrets to keep, identities to hide, and answers to find. When the certain darkness threatens to take Oriana away, will the Dragon be able to protect his mate?-----Excerpt-“If I knew you were my betrothed, I would have killed you the very first moment we met.” Arlan's gaze darkened with hatred.“If I knew I was betrothed to you, I would have killed myself before you even killed me!” Oriana mirrored the same emotions as him.He pulled out a dagger and offered it to her. “It’s not too late. Just slit your throat with this and you'll bleed out painlessly.”She accepted the knife, her fingers clutching its handle tightly. The next moment, he was pressed against the wall and the knife was on the right side of his neck. “How about I try it on you first, my betrothed?”“Feel free to try. But when you fail, this knife will first taste your grandpa's blood, then yours.”Anger rose in her eyes, and the next moment, blood was flowing through the right side of his neck. She cut deep enough to severe an important blood vessel.“You should not have challenged me,” she sneered and stepped back, waiting for him to collapse.He simply smirked and brushed his finger along the deep wound on his neck. “Seems like you failed.”She watched the wound on his neck heal on its own and felt shocked to her bones. “You.. what are you?”“Guess?”

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

- Description from novelupdates

The protagonist travels through Shu Mountain and becomes a demonic dragon guarding the heavenly book in Dinghu Peak.