https://wccftech.com/xenoblade-chronicles-definitive-edition-expert-mode/

Xenoblade Chronicles Definitive Edition will feature an Expert Mode that can make the whole game more challenging.

This new mode, which has been revealed by the series' Official Japanese Twitter profile, will allow players to distribute the earned EXP however they wish, so they can decide to make a character overpowered or keep the entire's party level low to make battles more challenging. Additionally, it will also be possible to level down characters, with experience points getting refunded.