Someone is bound to a System and must live out a failed life as a loser.
System: You can only accept the character's original bad ending and meet your end.
Someone: Got it. I can change the process, but not the outcome. That leaves plenty of room to work with.
.
Arc One, The Founding of the White Night Kingdom: Orobashi, the serpent god slain by Raiden Ei
After losing to Morax, the God of Precious Metal, in the Archon War, Orobashi fled to Inazuma. When he couldn't beat the two Raiden sisters there, he escaped to the Dark Sea. In short, this was an unlucky god forced to flee from place to place after taking two brutal beatings.
Orobashi had nowhere to set foot in Teyvat, and he literally had no feet: his true form was a colossal white serpent that could soar through the sky and burrow beneath the earth.
When Orobashi woke up in the sea, he swallowed countless fish and shrimp. He had a wonderfully carefree time in the water, and couldn't have been more content.
But more than ten years later, he accidentally fell into Enkanomiya. A frail, bedraggled child begged him to become the guardian deity of the White Night Kingdom. Only then did he realize that fate had arrived centuries early. He had no choice but to take in the people of the depths who lived in the White Night Kingdom ahead of schedule, following the plot. Before he knew it, he had made the kingdom more prosperous than Inazuma above ground.
System: No matter how you try to change things, you will die at the appointed moment.
Orobashi, absorbed in infrastructure development: You can't imagine the joy of building things.
Many years later, he died, but not by Raiden Ei's blade. The White Night Kingdom and Inazuma had since become close allies, working together for mutual benefit. He was simply talking with the chief administrator who had served him for years about the harvests of the past, and then, in the very next moment, he suddenly dropped dead.
Many, many years later, the death of the god Orobashi remained an unsolved mystery. But his people believed the Heavenly Principles had killed him, and stubbornly continued seeking justice for him, even going so far as to declare war on the Heavenly Principles.
Epilogue:
["If death awaits me at the end of fate, perhaps I can still do something for my people before I die." These are the famous words of Orobashi, the Great Watatsumi Deity and Feathered Serpent God.]
"Yes, those are the words our Feathered Serpent God spoke with his own lips."
"But every one of us believes He will return."
When a certain blond first set foot on Watatsumi Island, the Divine Priestess Sangonomiya Kokomi pointed out the inscription beneath the enormous serpent god statue and explained.
"By the way, Traveler, would you be interested in taking a commission to explore Enkanomiya? Legend says the Feathered Serpent God left countless treasures there." The shrine maiden smiled.
"Of course."
[World Quest: The Old Tale of the Deep Sea, Death of the Feathered Serpent God, has begun.]
[Please note: The following story is closely connected. For the best experience, please make sure you have enough time to read it.]
Arc Two, Old and New Mondstadt: Decarabian, the tower king who was overthrown
The tower king Decarabian found a wind spirit. Wanting it to help him find the predecessor of Barbatos, he raised the wind spirit as his son.
He never expected the wind spirit to run away from home one day. When it returned, it said it had met a human named Venti, who was willing to share his name.
"From now on, my name is Venti!" the little wind spirit declared. His stern father, the God of Storms Decarabian, responded by hanging him on the door to make him reflect on running away.
"Hey! I'm not a wishing doll!" the wind spirit protested.
Wind spirits are all born from the wind of freedom. A nameless wind spirit was taken in by the god of storms, and from then on lived under someone's protection. The spirit and the god made countless promises to visit the highest mountains and the widest seas in Teyvat. Back then, the spirit believed every one of those promises would come true.
"My friend taught me to play the harp! Want to hear?" the wind spirit asked, pressing close to his father's ear.
"Later. Maybe tomorrow. And stop tickling me. Venti, you know I'm busy." The busy god answered without looking up from his administrative work.
Tomorrow came, and the fierce winds of Mondstadt stopped without warning.
["Every gust of wind carried Decarabian's soul." From Ode to the Old Wind God]
Epilogue:
"So Mondstadt once had two wind gods?" the blond asked.
"Yes. Lord Decarabian's statue, which he held in his arms, is still in Old Mondstadt. It's just west of Mondstadt City, where you'll find a beautiful ancient city. That's what we call Old Mondstadt, once ruled by the old Wind God."
"Speaking of which, Lord Dvalin, one of the Four Winds, seems to have awakened too. If you're lucky, you might be able to see him if you head back to Old Mondstadt now. I wish I had the time to ask Lord Dvalin about the legendary God of Storms."
"Travelers, would you have time to help me find Lord Dvalin? Please take it as a commission."
"No problem."
[World Quest: The Old Tale of Mondstadt, Trapped by the Tower King, has begun.]
[Please note: The following story is closely connected. For the best experience, please make sure you have enough time to read it.]
Three: Tayzzyronth, the Swarm King crushed by a hammer blow from Qlipoth.
Four: ...
P.S. There are a great many original elements. The protagonist has a different name in each arc, but it's the same person.
Theme: Spread kindness, truth, and beauty