Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 15Book 5: -3: The Broken Empire

He had been reincarnated, he thought that he didn't cheat until suddenly he noticed someone invite him on a group chat.[Do you wish to join Dimensional Chat Group?]MC: "Accept!"---------------------------------------------Cover not mine, it's from anime Yosuga no Sora---------------------------------------------https://www.patreon.com/akikan40Maybe I'll be full of energy to write your favorite fanfic.

A little ruffian who fought recklessly without any morals and bottomline accidentally time-traveled to parallel space and became a Key Case Investigation Team agent. The huge change in identity had him creating chaos in the police station. However, a strange miracle system helped him repeatedly solve mysterious cases, turning him into an impudent ruffian detective!

An ordinary student, a wretched peeper, a cowardly teenager with a kind heart. In a terrorist attack, he inherited the knowledge of countless elites, embarked on a path of God Jagged Tu…

He is an artist!

He is a mathematician!

He is a psychology Doctor!

He is a master of fighting!

In fact, he is a man

Taken off raw site:

A wretched, dirty young man is working during the summer when he was caught up in a mysterious explosion. After that explosion, the young man is then left with the memories and knowledge of dozens of the world’s experts.

He has changed, his heart has become cold, iron-blooded. He became a killing machine, his mind turned mechanical, calculative. Everything goes according to his plans and calculations!

In this magical, slaughterous world, a door is opened for him…

- Description from Novelupdates

“Reincarnated into the World of Magic as a demon, the last thing Davis expected was to grow up right amidst the arms of angels. Ever since the group of philanthropic angels took pity on his miserable birth and adopted him, Davis has been forced to keep his evil identity a secret while he signed in to the system.

“”Ding! The Host has signed in at Angel’s Pond, ‘The Saint’s Halo’ is rewarded!””

“”Ding! Devil’s blood activated. Sign in error. ‘The Devil’s Curse’ is additionally rewarded!””

“”Ding! The Host has signed in at God’s Throne, ‘Gold’s Holy Axe’ is rewarded!””

“”Ding! Devil’s blood activated. Sign in error. ‘The Devil’s Manifistation’ is additionally rewarded!””

After a thousand years of quietly signing into places in the City of Angels and being rewarded with double the rewards, Davis’s true identity finally came to light! Now as a true Devil, Davis had both the world of angels and demons surrendering at his feet!”