Tensei shita Last Boss wa Isekai wo Tanoshimimasu

The protagonist, Shion, knew that he would eventually meet his demise. This is because "Shion Granbania" was the strongest final boss in the highly popular game Fantasy of Arcadia in his past life. Over the course of several years since his reincarnation, Shion has managed to break every flag that would lead to his downfall. Now, having finally attained freedom, Shion sets out on a carefree journey to enjoy the world of the game he loved. However, someone with the power of the strongest final boss should never be able to live as an ordinary person.