The Evil Villain Turns Out to Be My Wife

Shen Lan, a high school student from the 21st century, wakes up one day as an unloved eldest prince in an ancient kingdom somewhere in the West. Here, humans aren't the only race. The dragons possess such overwhelming power that they stand above all others, feared and hunted by everyone. Shen Lan: ... Not a big deal. This world is actually a book, complete with a protagonist couple and a villain. There's also Shen Lan, a devoted simp who has loved the protagonist on the receiving end since childhood but never stood a chance. The story has reached the point where he's risking his life to pick forget-me-nots and break up the couple. Just as he gives up on picking them, his half-brother tricks him into a dungeon. Shen Lan: ... Not a big deal. The dungeon is empty. All it has is a heavy door that won't budge and one other thing: a man? Long silver hair, narrow phoenix eyes, beautiful ocean-blue eyes like glass beads, and a dark red robe casually draped over his shoulders. Isn't he the wine seller Shen Lan rescued on a whim yesterday? Shen Lan: ... N-not a big deal. One night, while Shen Lan was fast asleep, he suddenly felt a weight settle on top of him. The wine seller sat astride him, slowly opening his clothes as he murmured, "I'm so hot. Help me." Shen Lan: ?! Now this is a big deal! * Nidhogg, the leader of the dragons: cruel, vicious, sinister, greedy, and the embodiment of every evil. To escape the dragons' mating season, he sneaked alone into the human kingdom to steal a potion. After his mission failed, his mating season suddenly began. His power rapidly waned, forcing him to hide in a tavern. When a drunkard harassed him, he fled into the dungeon. And then he was locked in there with a human. Nidhogg: ... To survive, he swallowed his pride and sought out the human. The first night: Nidhogg: Once I get out of this door, I'll kill this human! The tenth night: Nidhogg: Kill him! Kill him! Kill him!! The thirtieth night: Nidhogg: Maybe I don't have to kill him... The ninetieth night: Nidhogg: Mm-hmm~ After they got out, the human slipped away, while Nidhogg was taken back to the palace by his subordinates. Looking at the potion they brought him, he suddenly felt he could do without the useless stuff. * The next day, the dragon leader went missing, and the unloved eldest prince of the Kingdom of Bili had a handsome wine seller by his side. Everyone was envious. But some people were also curious: why did the eldest prince look more and more haggard? Core message: Sincerity is the deadliest weapon