The trail of the Ice dungeon puts you up against your "dark side"
but Hajime is SO AWESOME, he just brute forces it, Kendo girl learns that she is a cockslut deep at heart and wants to jump on hajimes cock, Kouki gets shat on again, and by the end gets cucked by his last friend, from here on out Kouki will be nice little cuck that just stays and sees how all the girls swoon for Hajimes penis.

Later on Hajime defeats god, has his orgy with all the girls, including the teacher and the princess, goes back to earth, with the powers of a god, changes his appearence to look like he was, and is met by his mom and dad, and they both accept the harem of girls, also his mom is a SUPER FAMOUS MANGAKA, and his dad is the CEO of the most Succesful VIDEOGAME COMPANY EVER!

He goes on to rule the world and his wives get worshiped as goddesses.

Each of the dungeons is designed around a 'trial'. Orcus, for example, is building up combat experience with various monsters, while this one is to not rely on magic and not get mad by being taunted repeatedly. And, the labyrinths self-regenerate over time, so if it is destroyed, eventually the last boss, or anything else, will reappear again. However, it is unknown how long that would take.

Each of them protect their labyrinth with various things and prevent anyone unworthy from getting the 'Age of Gods' magic at the end.

Every liberator but Miledi (who was turned into a golem) is dead, so they cannot 'team up' to kill last boss.