Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 6 - 6-10. Magic Circuit and Rose Engraving

Deep Sea, the mental network connecting the Five Continents, is rapidly propelling human civilization forward, but no one knows that eternal night is coming. When the transcendence awakens, the grand buildings will collapse. When flesh and blood are bitter and weak, how can people ascend? The tale begins with an encounter and the receiving of a ruler carrying truth. Gu Shen, an ordinary young man, unveils a corner of the truth about this transcendental world and becomes the largest moth among thousands being drawn to a flame. When the bitter winter comes… I will ascend against the tide, overturn the thrones of kings, shatter the crowns of hypocrisy, and destroy the scepters of injustice. I will become humanity’s final Light Barrier.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

At five years old, the child from the metaphysical family is about to leave the mountain, and the bigwigs of the capital city have come out to see him off.What's so great about a little dumpling?Yun Xiaoqi innocently spreads his hands, claiming he never intended to show off his powers; his simple wish is to be a good child while subtly dominating all sorts of spirits.Many oppose him during this time, and the “Little Celestial Maiden” Yun Ying teams up with various metaphysical leaders to continuously challenge him, only to be soundly beaten, losing face.Finally, the bigwigs bow down in reverence: it’s we mortals who were blind and offended the little ancestor!***The news of the little dumpling ruling over the metaphysical world reaches the Nether Realm.The Lord of the Nether Realm frowns: this milky little master must be the youngest and most temperamental special envoy from the Nether Realm.The little dumpling, carrying a lantern, walks among the mountains and rivers of the earth, guiding the souls with a proud stomp, declaring: Lord of the Netherworld is not much older than me, who are you calling childish!The noble and refined Lord of the Nether Realm lands and transforms into a twelve-year-old boy, gentle as jade: whatever the little envoy says is right.Yun Xiaoqi keeps waving his hands: nope, I'm just working here.

The two faced number one female spy transmigrates to a different world and becomes an outrageous idiot girl. When she woke up, what she had to face was consecutive blows of the decline of her family clan, her crippled martial skills, and her disfiguration. To protect her family, she must obtain the treasured book, obtain outstanding achievements, summon a dark beast army. Wait and see how in this unfamiliar, dark magical continent, she dies and becomes a demon then steps up to the top, making all of the formidable people in the world bow down to her in respect.

- Description from Novelupdates