Shiitagerareta Kyuuseishu no Ore wa Isekai wo Misutete Moto no Sekai de Kimama ni Ikiru Koto ni Shita

Kazama Shinji was summoned to another world, which he saves due to a plea from a goddess. However, the world as a whole only looked to use him and oppressed him. Having realized how ridiculous it is to continue working hard for that world, Shinji fulfills the bare minimum of his duty, then abandons the world, returning to the real world with his cheats still in hand. As the world he abandoned falls into ruin and self-destruction, he shall live as he pleases within the real world with the help of his cheats. Source: NU