He's My Fiancée ! : I Went Back To The Past and You ! - Chapter 317 - 318: Adam and Andy-II

Transmigrated into the world of High School DxD, Roy believed he had been handed a life of luxury and glory. Born into the prestigious Lucifuge family, with his Sister Grayfia as his strict yet devoted older sister, he thought he was destined for greatness. 99,997… 99,998… 99,999… 100,000!!But... reality proved harsher: Roy lacked demonic talent and, despite years of training, remained a Low-Class Devil. his peers effortlessly achieve High-Class status, he’s been trapped in a cycle of endless sword practice and ridicule. Yet, he refused to accept mediocrity. Ten thousand sword swings a day, relentless training.. Until one day..[Ding! The Strongest Demon King System has been activated. Access functions to learn more.]---- High School DxD - Main World!1 - High School of the Dead [●] - First2 - Demon Slayer [●] - Second3 - Akame Ga Kill [●] - Third4 - Bladedance of Elementalers [●] - Fourth5 - Campione [●] - Fifth

“Does the vengeance of justice count as a sin?”Fushimi Shika, burdened with a system, gives his answer: “Yes! But I will take on all sins!”Avengers chant his name, leaving behind his name. Thus, the world gains a notorious serial killer.A grieving father avenges his lost daughter by killing the true perpetrator;A husband takes revenge for his wife through a locked-room murder;A child who lost both parents makes a desperate gamble...Fushimi Shika shields these unfortunate souls who have lost everything, leaving his unique proclamation at the scene:“This is divine punishment, I am the divine punishment”...Years later, atop Tokyo Tower, Minamoto Tamako points a gun at her partner.“Although I don’t know how you did it, you are the mastermind!”Amidst thunder and lightning, rain pouring down, Fushimi Shika raises his hands:“How rude, Rabbit Officer, I am a messenger of justice.”

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

“Transmigrate as the Final Villain of the novel...” Ark stared at his reflection in the mirror he held. It was Theos Von Fallen, the final villain of his favorite novel.Although he was the final villain and the strongest in the novel, he was killed by the protagonist and his harem in the finale.[Ding. The Heroine Snatching System has started] Ark gave a crooked smile when he read the system message in front of him... “Exchange!” he shouted, unwilling to accept the fate they had in store for him.Trapped in the world of his favorite novel as the most “evil” and powerful villain, Ark, now Theos, will use his knowledge as a fan obsessed with the novel to take away all the protagonist's opportunities.Whether he can become the focus of the whole show or whether a script will dictate his fate, he will decide! He will live as a true villain who doesn't care about anything but his life and his loved ones.