Your Highness, Stop Pretending. You’re Just a Substitute

[Pure historical romance + stand-in + both pure in love + domineering possession + the male lead turns into a deranged, twisted lunatic later on] On her wedding day, his phoenix eyes burned with madness and obsession. "Shen Yanxi, if you dare marry him today, I will destroy the whole world." The regent brought a stunningly beautiful woman back from the countryside, and everyone assumed she was madly in love with him. Gu Ci thought so too. He plotted at every turn, all so she would fall into the trap he had carefully laid for her. Little did he know, it was all under her control. He had always believed Shen Yanxi truly loved him. It wasn't until he saw her leaning in someone else's arms, wearing a sweetness and happiness she had never shown him, that he realized how utterly ridiculous he was. In the end, he was the one who had fallen into her trap, while he had foolishly thought he held a place in her heart. Only Rong Jing knew that A Yan belonged to him, but the one who had returned now was his Xi'er.