Shinwa Densetsu no Eiyuu no Isekaitan - Volume 6, Prologue

Qiao Chen was mysteriously transmigrated to the interstellar era. As an adult from his original world, he was forced to grow up all over again in this new one. Now, out of nowhere, he was requested (forced to take on) with the inexplicable task of jumping from world to world to save the high general’s soul.

Throughout his journey, Qiao Chen finds that these worlds and bodies he’s jumping in and out of are his previous reincarnations. Whether or not these all culminate into coincidences or a predetermined destiny, there’s things that must be done while completing the main task:

-Avenge his past life

-Take revenge

-Fulfill past regrets

-Realize those lost dreams

-Make up for past failures

Since God has given him these opportunities to rewrite his fate, why wouldn’t he be pleased to start-over?

- Description from Novelupdates

“No matter what I would do, my actions would inevitably change the story. I knew this already.... But what do you mean that I changed the plot even before reincarnating in the novel!? ”

...

Should I follow the plot of the novel? Or should I do as I wish? Maybe I should follow the plot while making changes favorable to me?

These would be the first questions of those who reincarnate inside a novel. However, due to a certain event, Sol didn't have that luxury. He had already influenced the plot.

The change he created wasn’t small either. If nothing was done, the novel would head for a 100% certain bad end: Destruction of the multiverse.

Luckily for Sol, the plot of the novel had yet to begin. It would take a few months before everything starts in earnest and all the dimensions combine, bringing along the dying worlds and their catastrophes for the Great Merge.

“Yes! I will enjoy my life to the fullest!”

Calamities? Future Catastrophes? Inevitable Destruction?

Sol doesn't care for those things. He has a single aim, to live a life that would make even the Gods jealous!

Be it the hero who brings hope, the villain who crushes the protagonist, or the enigma who controls everything while staying in the background. Sol will switch to any role that benefits him.

But will everything go as he has planned? The longer Sol lives in this new world, the greater mysteries he comes to face. To start with, his new identity itself is….

In the era of universal mechas, people can go to the endless abyss, collect materials, strengthen and forge their own mechas, and master the power of destroying the world.

Jiang Chen traveled through time and awakened his talent [Immortal Unarmed]. Once the mecha is broken, he can permanently absorb its power and receive multiple bonuses.

…

At the bottom of the abyss, when the Old Demon God finally broke the Titan mecha with great effort, a hand stretched out from the fragments and held down its head.

“Congratulations, you have unlocked my limiter.”

- Description from novelbuddy

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.