You are Monkey D. Luffy's identical twin brother instead of being a pirate you instead became a marine.

Tensura x Male Godzilla Reader You and your buddy Satoru were going on about your day as usual before heading to work, when suddenly, out of ALL the chances, both of you lost your lives at the SAME EXACT TIME. Thinking it was over for the two of you, you vowed to make sure your once mundane life would never repeat itself if you were ever reborn and that you'd be even more amazing than before. What you didn't expect was to start your new life as a monster being born in a new world. But hey! At least you have your best bud with you! Some images used in the story are not mine or owned by me, and are created by and owned by the anime/manga.

RWBY X Male reader but you're an appropriately powered Isekai hero Whilst on a walk Mark Oath is attacked by a girl he rejected earlier that day and is sadly killed, but what's this? A sleep-deprived kid wearing way too much grey saying he's God? Reincarnation? A whole new world with new abilities? I get to keep my power? Man, this is pretty interesting.