Jukokuin no Tensei Boukensha: Saikyou Kenja, Jiyuu ni Ikiru

The great sage, Grameos, tired of his current life as a famous mage, decided to reincarnate as a young boy 200 years in the future. Before reincarnating, he places two magic restraint seals on his hands, so that he can hide his enormous magical power after he is reborn.

His motto for the next life is "Hide my powers, don't stand out, and be free".

[web novel](https://ncode.syosetu.com/n9110fe/) (jp)

Official English Synopsis:

At a young age, Grameus became infatuated with magic and continued to make a name for himself, eventually given the title of a Sage. Thanks to his tremendous power, his days were spent in boredom as a do-gooder, helping the people in need and defeating monsters. Tuckered out from such a restraining life, Grameus decides to leave his current life behind, preparing a spell that will let him be reborn 200 years into the future, while also engraving two “Curse Marks” onto his hands, which act as magic inhibitors to limit his power. Gaining conscience as the young boy Chris, the former Sage now begins his second life while ensuring he would finally enjoy the freedom he could never taste before.