MTL - The Counterattack System is Only Available In the Mahayana Period - Chapter 690v2 tell the truth

A 13-year-old deaf teenager living in the 21st century suddenly found himself as a young boy in Japan during the early 1900s. With two World Wars, two nuclear bombs, Hitler and many other disasters awaiting his future, he thought things couldn't get worse.Except it did.He found out later on that he had actually reincarnated into the world of Demon Slayer where man-eating demons ruled the night. He thought things couldn't get worse.Except it did.But hey! At least he had unparalleled talent, incredibly special eyes and future knowledge.How will the story of Demon Slayer change with the addition of this unique character? Will so many still die if the Hashiras had one more pillar in the final battle?Or will the story end on a much happier note?

Lumberling, a 42-year-old civil engineer, grew numb to the monotonous rhythm of modern life. Hoping to rekindle his sense of wonder, he set out on a solitary nature trip, only to stumble upon an ancient, forgotten pyramid. A strange red light burst forth, killing him instantly… and binding itself to his soul.Cast adrift in the void, his soul found no rest, until he awoke in the body of a young foot soldier, bleeding and broken on a war-torn battlefield in a world not his own.Determined not to die again, Lumberling fights to survive in this brutal new realm where knights clash with monsters, kingdoms rise and fall, and mysterious powers shape the fate of nations.Armed with a strange ability to devour the essence of those he slays, he begins to carve out a new path, one forged by blood, strength, and sheer will.But power alone may not be enough. In a world where danger lurks in every shadow, and ancient forces stir in the dark, can a lost soul rise above fate… or will he be consumed by the very essence he seeks to control?

Once through the pirates, Lu En became the son of Monkey d Dragon, a grandfather named Monkey d Karp, and an unreliable and neurotic younger brother named Luffy.

Fortunately, the ghost back system is activated!

The completion of the ghost back is 10%, and the training effect is increased by 100 times!

The completion of the ghost back is 20%, and the training effect is increased by 1000 times!

…

One day, Lu En, a ghost-backed master, appeared in front of Luffy who was shouting to go to sea, and made Luffy cry on the spot.

Luffy: “The pirates in the sea are all monsters like my brother? I don’t want to go out to sea!”

Garp: “For a long time, the two boys, Long and Luffy, with small arms and calves, I really doubt that they are not my sons and grandsons. Like Lu En, they are the grandsons of the old man!”

Warring States: “The strongest creature in the sea, land and air is Kaido? No, it’s Lu En!”

- Description from novelbuddy

Jeon Eun-woo has lived for almost thirteen years in isolation in a cell at the Blackwood Research Center.He doesn't remember who he is, he doesn't know who locked him up, and he doesn't know why he's still alive.The apparent calm with which he has lived is shattered when he is assigned a cellmate.Rhys, a young man with invisible scars, appears in Eun-woo's cell with one goal: to kill him.Because Eun-woo is not just any person.He’s the last living Esper.But upon coming into contact with Eun-woo, Rhys unexpectedly bonds with him, something that shouldn't be possible because Rhys isn't a Guide.Or is it?