The Reincarnated Assassin is a Genius Swordsman - Chapter 665

What happens when a scientist from a futuristic world reincarnates in a World of Magic and Knights? An awesome MC is what happens! A scientist’s goal is to explore the secrets of the universe, and this is exactly what Leylin sets out to do when he is reincarnated. Dark, cold and calculating, he makes use of all his resources as he sets off on his adventures to meet his goal. Face? Who needs that… Hmmm… that guy seems too powerful for me to take on now… I better keep a low profile for now. You want me to help you? Sure… but what benefit can I get out of it? Nothing? Bye. Hmmm… that guy looks like he might cause me problems in the future. Should I let him off for now and let him grow into someone that can threaten me….. Nahhh. *kill*-

Alternative: Leylin is transported from an advanced technological era into a medieval world— except there’s magic. Equipped with “only” his quick wits and an A.I. chip fused to his soul, he sets out to become the most powerful magus the world has ever known. In a land divided into the Light and Dark Magi, the weak can either be cattle or disposable slaves. Only the strong can determine their lives, and only they have the luxury for virtue. Yet strength is only a tool for Leylin, like any other. His goal, in the end, is his own.

In a world where survival depends on victory in an alien battlefield, warriors are assigned a crucial keyword that determines their fate.With attributes that rapidly grow when aligned with their keyword, they gain superhuman abilities.But if their persona collapses, they weaken. In this apocalyptic-like world, acting skills are paramount.Acting is sustenance, glory, privilege, and life. Join the battle and discover the true meaning of bravery, cunning, righteousness, and more.

Shaymon, the man who has achieved the apex of dark magic, is framed as being a Demon King and is killed.

Swordmaster Karyl MacGovern.

He returned to the past, wanting to rewrite the future he was unable to change with his sword alone. And this time, he would acquire the power that once eluded him—magic.

This time, he would master both sword and magic, and stand on the peak.