Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 4 - 4-6. Carriage and Coachman

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

The NPC sets out on a journey to defeat the Demon Lord, joined by beautiful girls he meets along the way.---This is an NSFW story, so if you're under 18, turn back now, son. No NTR, and no full-on Yuri. There might be slight Yuri—like girls kissing and stuff during threesomes—but it's not that kind of Yuri where the girls fall in love with each other while in a relationship with the MC.---

Young genius Ren Zhong, suffering from a terminal illness, chooses the human cryonics project. Upon awakening, he finds himself in a desolate wilderness, beneath a gigantic blue sun and a duo of silver-white moons. On this unfamiliar planet, relying on the resurrection to rewind time and accumulate experience, Ren Zhong is determined to become a warrior. After experiencing betrayal, being wanted, and judged, he resolves to rebel against this unjust world and establish a new world order through war.Compress infinite time into a moment; anything can happen.Rising from insignificance, walking the seams of time, reversing billions of years of enslavement.This is the story of an immortal man and his comrades breaking the shackles of fate.

Mu Xiaoya lived for twenty-six years before she knew that she had a sudden genetic disease. There was no medicine for it, and there was only death waiting for her.

Before she died, many people came to see her, but she was most impressed by Bai Chuan.

Bai Chuan was her neighbor, an autistic child with scholar’s syndrome. At that time, his face full of scars was desperate: “I – I studied all your medical records, but I have no way to save you.”

Mu Xiaoya was stunned: “You are a doctor?”

Bai Chuan: “I am not… …”

Mu Xiaoya’s disease was a genetic disease. Unless the gene was changed, there was no possibility of cure. However, Bai Chuan was the only person who tried to cure her after she fell ill.

Mu Xiaoya: “Why are you going to cure me?”

Bai Chuan: “I want to marry you.”

Mu Xiaoya laughed: “If you marry me, you will soon become a widower.”

Bai Chuan insisted: “I – I want to marry you.”

Bai Chuan, who has cognitive impairments, can’t express his meaning very well, and can only repeat it over and over again.

Later, Mu Xiaoya still died. When she woke up, she returned to the summer of her college graduation.

Bai Chuan: “I… I want to marry you.”

Mu Xiaoya: “Good.”

The starlight in the eyes of Bai Chuan was the most beautiful scenery that Mu Xiaoya had ever seen in her life.

- Description from Novelupdates