"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.
It ruins the characters with the nonsense about threesomes and such, because it makes them flat, lacking any dignity. It would have been much better to have handled a secret relationship dynamic if you want to make the character a womanizer. Although, for me, the best thing would have been to simply create a romantic storyline between Brian and Letty and Mia alone, without Mia or Dom knowing, where Bryan eventually falls in love with Letty. Trying to maintain the characterization and character of the characters. It's also not necessary to justify Letty cheating on Toreto by first making Toreto a cheater or an idiot. That would have given the story more credibility and impact, instead of wish fulfillment and characters driven only by lust.