The Strongest Sage with the Weakest Crest, Volume 6 (The Strongest Sage with the Weakest Crest #18-20)

In this manga adaptation of the popular light novel series, the world's strongest sage will stop at nothing to get stronger... not even reincarnation!
Once the world's most powerful sage, reborn Matthias has gained the optimal crest for magical combat many thousands of years in the future. But with magical knowledge at an all-time low in this new era, no one recognizes Matthias's crest for what it is, and it will be an uphill battle for the twelve-year-old sage to prove his greatness to everyone!

With the demons seeking to eliminate all who are aware of their plot to cripple mankind through magic disinformation, Matthias stands on the frontline of the battle... but he's not alone! He's got the legendary dragon Iris by his side, not to mention the students of the Second Academy who've been training to unleash their full potential. Together, they'll fight back against the all-powerful demons!