Shikkakumon no Saikyo Kenja-Sekai Saikyo no Kenja ga sarani Tsuyokunaru Tame ni Tensei Shimashita 20 (Gangan Comics UP!)

[Machine Translation] The best and wisest, become a lord! What is the best way to manage a fiefdom...! A wizard who was once called a "sage" is reborn in the future in search of the best sigil for magical combat. However, in the future where magical theory has degenerated, the desired emblem is called a "disqualified emblem" and is despised. It was the demon tribe that distorted the information in the sigil and degenerated the magical theory. Matthias is engaged in a battle against the demons who are trying to destroy humans! After destroying the strongest and worst demon tribe, Matthias is anointed as a nobleman as the new lord of the city from which the lord fled! There is supposed to be a labyrinth near that city, but because it was sealed, a magical disorder occurs, causing a large number of demons to arise...

最強賢者、領主になる！最強の領地経営法とは…！？かつて【賢者】と呼ばれた魔法使いが、魔法戦闘に最適な紋章を求めて未来へ転生。しかし魔法理論が退化した未来では、望んだ紋章は「失格紋」と呼ばれ蔑まれていた。紋章の情報を歪め、魔法理論を退化させたのは魔族。マティアスは人間を滅ぼそうとする魔族との戦いを繰り広げていく！最強最悪の魔族を撃滅したマティアスは、領主が逃げ出した街の新たな領主として貴族に叙せられる！その街の近くには迷宮があるはずなのだが、封印されていたため、魔力障害が起こり、大量の魔物が発生することになってしまい…。