A man named Leo died and has been reincarnated into Twilight with some wishes

(warning: second chapter is pretty dark) I wanted to write about a guy similar to L from death note and I couldn't really do that without some dark back story. I want him to be high iq but the mc only be as smart as the author and I'm not that bright, so expect some mistakes unbefitting of a genius although I'll try not to. Also I'm sorry for the cliche of being Bella's brother but I don't know how to make him telepathic immune without wasting a wish. I'll probably add some 18+ scenes

bit of a rant
And I'm going to buff the vampires slightly with higher Regen and speed because of the inconsistency on there abilities, like how "they are too fast for the eye to see that they are basically invisible" yet can only run at 100 mph (fyi a MLB player can hit a 105 mph baseball) or how the Cullins need thunder to play baseball because of the booms they make, which would mean they are hitting at the speed of sound which means Edward is fast enough to catch something going 767mph and that is impossible at their 100 mph speed.