SENYUU.

Satan Rchimedes returns to the earth after being sealed for one thousand years by a hero. The King tries to seal Satan once again by dispatching descendants of the hero. However, it's troublesome to find the genuine descendant, so the king chooses 75 hero-like people. This is the adventure of Alba, hero no.45, and his monitoring fighter Ross. — Description from AniList community (anilist.co).