"An everyday man gets thrown into the world of twilight thousands of years before the start of the plot. With immortality and incredible abilities. How will this man's presence change the outcome of the original story?" [ this is a slow-burn fanfiction; the MC is just trying to experience life and enjoy it, not to take over the world and rule from the shadows.] I do not own twilight or the characters of the twilight world, all that belongs to me are my own characters.
Hope I don’t regret the rating, I’m letting it marinate before consumption. I’ll read it maybe around 100 chapters. You can also go further with his quirk, like instead of just adaptation and evolution he starts being able to absorb quirk factors through blood and adding it into his quirk factor, like how Izuku does it from the fanfiction - Blood For The Blood God by Ryujin Maoi, it would give Tatsumi some diversity.