Climbing a Tower Which Even Regressors Couldn't Conquer

A friend who passed out while drinking suddenly said something strange. *"Su-Hyeok, I've regressed." "Regressed?" "Yes, I've come back in time." "Are you crazy?" "You are the only hope for humanity."* And then I was taken to the tower… But it doesn't matter! Regressor? Tower? Trials? Whatever it is, It doesn't matter but what I know is I'll conquer this goddamn tower! (Source: KakaoPage, translated)