The Villain Reborn as Game's Final Boss

In his previous world, X was a feared and brilliant criminal. He led a massive criminal organization, possessed sharp strategic intelligence, and had enough power to challenge entire nations. Though ruthless, he lived by his own principles and morals. One day, after completing a fantasy war game in his free time he transmigrates into that very world. But not as the hero. He awakens in the body of Kael Frost, the game's final villain. In the original game, Kael was a noble born into the Frost Dukedom, which was the strongest after the royal family. He had no interest in training or holding his families legacy despite being the heir to the House Frost. He was a prime example of a spoiled noble brat. Seeing his constant failures and pathetic state, his family especially his father Castor Frost started to neglect him entirely. Discussions were held to appoint Kael's younger brother Kevin as the heir to the Dukedom. Enraged by his family's actions Kael began to behave in more pathetic ways as some sort of revenge. His relations with everyone started to deteriorate further and a public conflict during a grand banquet marked his complete breakdown from his household. Soon after, Kael disappeared from the society. A year later, driven by hatred and despair, he performed a forbidden ritual that granted him immense power in exchange for his emotions and sanity. The ritual succeeded, but turned him into a psychopathic mass murderer. Though powerful enough to nearly defeat the protagonist in the final arc, he ultimately lost due to his madness and the hero's many allies. That was how the game ended. This time, the transmigration happens after the ritual is completed. X inherits Kael's fully awakened powers while retaining his sanity, intelligence, and fragments of emotion from his previous life. With strength untouched by madness, he becomes far more dangerous than Kael ever was. 2 years later as admissions begin for the prestigious Namda Academy, the villain re-enters the world stage. Nobles are accepted automatically, while commoners must pass exams that test intellect, psychology, and potential. With knowledge of the game's future and the mind of a genius strategist, the final boss steps onto a new path.