In the novel, this door part was a bit more serious. The mc have analyze the potential risk of going inside an unknown door,the posibilities of being instantly killed ,being poisoned,lack of oxygen etc. Its a bit fresh to see that despite having some loose screw here and there, he still retain some sanity and some commonse sense. The part about him fighting army of people without any magic is also a bit more serious and had a distinct heavy atmoshpere instead or breezing it off like here. Although they joke about how Cid claims to be a champion if there is a tournament without magic...hayss i really wish they take the next chapter seriously though. Trust me, you will cringed but also feel your 8th grade syndrome creeping back in the next chap.