Datapack for Tensura: Reincarnated
Should work for any verison of tensura.
Allows you to reroll your skills upto 3 times. There's a config to change the amount of rerolls you get and etc.
There will be a chat message to reroll but incase you lose it you can do /trigger reroll
It will remove/reset your skills, so it's not recommended to do this mid-game or late-game as you will lose your mastered skills. You will gain back any skills gained from the race. (although I'm not 100% sure about custom races for example if they give something like black lightning)
Incase you want to edit the config just open the config.mcfunction file with any notepad/code editor and edit the Rerolls number to any number of rerolls you want to have.