The three main men of the Naville empire

That afternoon, the atmosphere of the party at the Duke of Ashgard's residence seemed lively. It was the birthday of their long-lost daughter, Elena and Leixa, their adopted daughter. Elena seemed to smile so softly, making those around her unable to take their eyes off her. Her return to the Ashgard family was a miracle that indirectly shifted their attention from Leixa who had been appointed to fill the void of the missing Elena, the youngest daughter of the Ashgard family. Duke Ashgard was seen talking with the other three main male characters: the crown prince, the leader of the holy knights and his first child, the young Duke, Loirk. Everyone preferred to get closer to Elena and were not interested in inviting Leixa to chat considering that Leixa had been known as a monster because she often caused chaos and was thirsty for affection. Not hesitating to punish anyone just because of a small mistake that could actually be tolerated. Based on the original story in the novel, soon Elena and Leixa would drink from the holy grail that had been prepared for them both as a form of self-purification upon entering adulthood. Without knowing that Elena's grail had been coated with deadly poison that made Elena critical and the main suspect was Leixa, because Elena's return to the Ashgard residence threatened Leixa's position as an adopted daughter. Leixa was executed the next day after Elena lost consciousness. A tragic end for the webtoon's antagonist.

Unfortunately, you've been transported into the Webtoon and taken over the body of the antagonist, Leixa. Just as the servant is handing the cup to Elena and Leixa, you must do something to save yourself (the survivor) from a tragic end and execution.