Shikkakumon no Saikyou Kenja
The Strongest Sage with the Weakest Crest
At birth, Mages randomly acquire a "crest" that determines their magical capabilities. Gaius was born with a crest specializing in creation, making him known as the world's strongest sage. He wanted a mark for close combat, so he decided to reincarnate to change his fate.
Thousands of years later, Mathias Hildesheimer reincarnates with his desired crest. But to his surprise, magic had grown weaker over the years and his crest was seen as the weakest. However, Mathias flourished in the royal capital's Second Academy and learns the dark truth behind humanity's downfall. He now works to fix the consequences of his absence.