Mc is a top hacker and played this game on earth in which he create a code for it with many cheats and modifications in the game. One day many cities were transported to another world full of monster similar to the game he played before, the cities are protected from outside treats by a barrier for 3 months but it doesn't mean they are safe as monster spawn inside the city every night. Every person Basically got a beast as a started but it does not mean that they can tame them right away and the Mc first beast was his first beast from the game and it still caries his memories from the game time just that his level is reset to lvl 1. Also Mc only got three cheats available while the others where erased which are 10x xp, grid space(more storage space than normal) and dungeon creation ( in certain circumstances Mc can create a dungeon but it's usage and rewards have heavy restrictions) even though he still has cheats Mc can't be said to be too op in my opinion because his beast potential are mythical his xp requirements are more than 10x more than others©(Mtnovel, Wtuloab)