Shikkakumon no Saikyou Kenja: Sekai Saikyou no Kenja ga Sarani Tsuyokunaru Tame ni Tensei Shimashita, Maou Gakuin no Futekigousha: Shijou Saikyou no Maou no Shiso, Tensei shite Shison-tachi no Gakkou e Kayou Recommendations
Reincarnated and very strong MC
The world has changed, things are different from how they were before