Harry Potter: Ero World - Chapter 18: Delving into Magic!

A muffled murmur sounded softly,

Crazy goblins ravage the village,

Mutated beasts roam the fields,

The ancient old gods are gradually awakening,

Just when the darkness is about to engulf the entire continent,

A brave man from another world quietly appeared,

This may be the darkest hour before dawn.

Human: “The savior has come?”

Monster: “Have new food arrived?”

Till the fame of the brave spread far and wide,

Walking through every corner of the continent,

He/she/they know,

What is the real darkest hour.

The monsters and humans said in unison:

“I beg you to be human, the ancient gods were so scared that they went back to sleep.”

- Description from novelbuddy

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

Damien Crowell was just a regular high school student who took a regular tunnel on his way to school—until one day, that tunnel spit him out into a completely different world. Instead of his usual path, he finds himself in a dark forest that stretches on for days, running on nothing but sheer stubbornness and a tiny water bottle.Just when he thinks he's going to die, he stumbles upon a castle straight out of a fairy tale (or a theme park) and promptly passes out. When he wakes up, he's in a prison cell, surrounded by confusingly handsome men who speak gibberish—until a beautiful, horned beastman with perfect hair and a translator necklace finally lets him understand.Now, trapped in a fantasy world where every guy looks like they stepped out of a modeling agency, Damien’s biggest challenge isn’t just survival—it’s trying to figure out why *he* always looks like a mess in comparison. Can he make it back home, or will he end up staying just to admire all the beautiful faces?Join Damien as he navigates a strange new world, awkward introductions, and a whole lot of unexpected feels in this hilarious, fantasy adventure!

There was a mysterious old man who approached the failed swordsman with the “100 million years button”. A magic button which can achieve the same effect as training for 100 million years if you push it.

The failed swordsman who pushed the button had his doubts, but immediately felt tremendous power rising in his body. So he pushed the button many times.

However it was a cursed button. The moment it was pushed, he was confined to the 100 million years prison of time. The first 100 years were devoted solely to training. After 1000 years he had forgotten why he swung his sword. He stopped thinking completely after 10,000 years had passed. After 100 million years he became crippled and finally managed to return to the real world. At the same time losing all his memories from the past 100 million years, the only thing that remained were his sword techniques. “I can become stronger just by pressing the button!” or so he thought and pushed the button many times after that. Foolishly trapping himself in that 100 million years of hell each time.

As he continued this loop, he began to think “If I destroy this world, will I get out of here?” A few billion years later, he finally escaped from the loop.

This is the story of a failed swordsman trying to make a name for himself in the world.