Gimai Seikatsu - Days With My Step Sister - Chapter 99: April 19th (Monday) – Asamura Yuuta

Jiang Chen, son of the Heavenly Emperor, unexpectedly reincarnated into the body of a despised young noble, thus embarking on the path of the underdog trouncing all commoners. No one has the right to call himself a genius in front of Jiang Chen, as no one has a better understanding of the heavens than the son of the Heavenly Emperor. “Genius? He who adheres to me shall ascend. Those who oppose me can find solace in hell!’

Ling Xiao was accidentally reborn into the zombie world and became Ninth Uncle’s younger brother.

Awakening the sky fire system can awaken endless strange fire.

At the same time, you can gain experience points, spells, magical powers, constitution and other rewards by burning all things in the world.

And at the beginning of the game, he awakened the mighty Qinglian Earth Heart Fire, and just as Mr. Ren came out of the coffin, he was burned to ashes by Ling Xiao’s palm.

“Senior brother Shi Jian came to kill him? Just in time, let him see how powerful the Nine Dragons Thunder Gang Fire I just awakened is!”

“The ghost king of Fengdu Ghost City is coming to arrest me? Just to show you the taste of hell fire!”

“Ding…Congratulations to the host for burning the sun, gaining experience points: 10 billion! Obtaining bloodline: Golden Crow Divine Body, turning into a new sun!”

………………

With the awakening of various kinds of different fires, and the improvement of his strength, Ling Xiao rose from a mere mortal against the sky, and finally burned the heavens and myriad worlds to create his own, the Great Dao of Heavenly Fire!

- Description from novelbuddy

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

The clock struck midnight when Ruelle heard the echo of footsteps. She tensed, the fine hairs on the back of her neck standing on end in the cool night air.“You shouldn't be here,” Ruelle whispered, her voice a breathless murmur. The silhouette finally came to stand under the moonlight, his dark red eyes watching her and his inky black hair ruffling.“Shouldn't I?” His voice was a dark caress, and she stood there captivated by the danger he exuded like perfume.“I haven’t seen you for the last two days,” his tone low. His hand reached out, fingers brushing against the silk of her nightgown, tracing the trembling outline of her collarbone. “Tell me, were you avoiding me, or perhaps... entertaining other offers?”Ruelle’s heart raced, her breaths shallow. She declared, “I don't belong to anyone.”“A bold claim,“ he murmured, his breath a tantalising chill against her skin as he leaned in. ”Yet here you are, pulse racing, your body tensed as if in anticipation of my touch.”His fingers gripped her chin, tilting her face towards his. The moonlight caught his eyes, revealing a glint of predatory intent. “Or must I remind you whose touch you truly crave?”