@Yulainei I've only read the first chapter so far, and I have quite a few things to say about it. I'll probably do another review for the later chapters if there are any glaring issues.
1. Prose
Good word choices and stuff, but you tend to repeat certain words multiple times within close proximity of each other, making the sentences choppy. In the first paragraph, you used "rain" three times (I'm counting the instance of rain in the word rainfall). In the second paragraph, you used "up" twice. These are a nitpicky thing, but your sentences will flow much better if you use more word variation. This is why English has a million synonyms for almost every word.
Another thing is that there are some incomplete sentences and some that are weirdly worded, making them hard to follow.
2. Omniscient POV
Be careful when writing in the third-person omniscient POV because things might get confusing if you switch to another character's POV. In the chapter, you switched from Nicolaus to the driver, but make sure that you clarify who is who. Give Nicolaus a distinctive feature instead of just calling him "that guy" or "that man." When the POV shifted, I wasn't sure who the speaker was, and who the speaker was referring to until I read a couple more paragraphs.
Also, make sure that you don't reveal too many of the thoughts in other characters' heads, especially if they're not one of the main characters.
Finally, you mainly write in the past tense, but sometimes, it changes to the present tense. Just stick to the past tense.
Tragic Backstory
Yes, Nicolaus may have a tragic backstory, but it doesn't feel impactful if it's narrated. Instead, it might be better to cut the narration altogether and just leave the MC with the feeling of rage and keeping it a mystery as to why he was angry.
Then, in the next chapter, maybe you could have the MC floating through time, watching the events of his past life unfold before him. With that, it would really cement the reason why the MC will no longer tolerate people who mess with him.
This is only one suggestion, and there are many ways to handle it. You can even sprinkle in his backstory while he in his new body.
That's about it so far. I'll probably keep reading to see where it goes.