I am planning to do a speedrun of this game and I am wondering if a Past% category will be added. Also would the timing for Past% start when your character is playable in the Past or on the Tutorial?

If you'd like to start with your character in the past, as long as you submit a run showing the dedication to achieve level 4 - level 36 and then to fuse, I would have no problem adding a category. There will be no question of adding more categories if more people have a preference of what they're going to run.

That's not to say there will be a category for every subset of run, but if there are a majority of people running the game a certain way, I'd be more than happy to promote that as a valid category