Toaru Majutsu no Index - Volume 14, Chapter 3: Something Far Removed from Magicians. Power_Instigation.

In a world where dungeons were an essential part of it, Rein was trying to conquer as many as possible. They were the key to gain powers in the fastest possible way. So, to reach his full potential and to become the strongest, he became a great dungeon conqueror.With his trusty friends and lovers, he was definitely going to reach the peak alongside everyone. Join Rein and see how he went from strong to stronger and then the strongest.__________________1. The harem would not be too large(I'm not sure how many but probably just 4-5 main and few other here and there). All the girls would be getting their time and story.2. The story is starting when the MC is in the middle of his growth stage and not at the very beginning. But his beginning will be mentioned in the story in some form.3. I don't think I need to mention this, but obviously it will not have any NTR, rape or that kind of stuff. It is actually quite a wholesome story focusing mainly on adventure, action and bit of romance and slice of life.

After thousands of years of silence, the world of cultivation once again welcomed the golden age.

Upon waking up from the dream, Josie traveled from the 21st century to Chicago in 1943, becoming a poor boy wandering the streets.

World War II? For Josie, who is still underage, it is too far away.

As an orphan, how he can survive in this age is the most important thing.

Fortunately, he has a plane trading system. In this era, being a master of time and space can make a good life if you think about it.

However, a few months later, Josie, whose life had just improved a little, looked at Captain America, who was singing and dancing with a group of girls on the stage of the war fundraising benefit performance, and fell silent.

It’s over, Barbie Q is over.

This is Marvel!

- Description from Novelupdates

The Hero’s party was attacked by a large group of powerful devils. The party will no doubt be annihilated if this were to go on.