What the best regressor story? Not time loop, but one trip back regressor story.
I tried the Reborn: Apocalypse series years back and remember liking it. A Summoner Awakens almost scratched that itch, but it hasnt had a new book in a while.
There was one I don't remember the name of, but the wrong guy gets regressed, so he takes up a trainer class to make sure the hero who was supposed to go back is as strong as possible. It was almost perfect, but I lost it.