Saikyou Onmyouji no Isekai Tenseiki

Even if you're the best exorcist in the world, power isn't enough to make you happy. Haruyoshi Kuga, an exorcist of unbeatable genius, is at death's door after being betrayed by the imperial court. Determined to be happy in his next life, he uses a secret reincarnation technique of his own creation to transport himself to another world. He is now called Seika and realizes that he wasn't cunning enough. In this new life, he decides to be more calculating, simply with the aim of finally finding happiness…