Shikkakumon no Saikyou Kenja

The Strongest Sage with the Weakest Crest centers on Mathias Hildesheimer, the reincarnation of Gaius, a legendary sage who once stood at the peak of magical power. In an age where mages are born with one of four crests, Gaius devoted his life to creation magic, but grew convinced that a crest designed for direct combat was the key to reaching his full potential. To pursue that ideal, he chooses reincarnation and awakens thousands of years later as Mathias, finally bearing the crest he had long wanted. The world that greets Mathias has changed beyond recognition. Magic has faded, the techniques that once defined the age of heroes are now treated as myths, and the crest he once pursued is dismissed as the weakest of all. When he enrolls at the royal capital's Second Academy, his overwhelming skill in every trial makes him impossible to ignore, and equally impossible to trust. As Mathias rises through the academy, he begins to expose the forces behind humanity's decline and the demons connected to that forgotten age. The series follows his push to prove that lost knowledge still matters, while the gap between the old age of magic and the present grows wider around him.