My legendary class is Husband Of Deathwill Sisters?! - Chapter 415: Death is the next step toward evolution!

Synopsis below:How did the Avatar universe change when a transmigrant appeared in an unknown village, long before the canonical events? And how are the two islands Kyoshi Island and Uzushiogakure no Sato (A village hidden in the maelstrom)?---Tags: AU, Before-canon, Post-canon, Violence, Death of major characters, Transmigration, Harem, Children, Incest, Romantic. Foul language.

Until he became the lowest-ranked master, his lonely and luckless life never changed.Suddenly one day, a descendant injected him with a nanomachine, and the machine started ‘speaking’ to him.[I am the seventh generation Nanomachine manufactured by Sky Cooperation, and I am operating as a central nerve connected to your brain.]“What? What are you talking about?”This was beyond the boy’s knowledge, he turned pale.The Nanomachine linked to his cerebrum realized the User was not understanding a single word it said.“Who are you, and why are you doing this to me?”[“I am the seventh generation Nanomachine.]“Nano Machine?”[Yes, Nanomachine.]The boy’s face hardened.Mashin was the deity the Mashin Religion worshipped, along with the Sacred Fire.The religions’ Master communicated with Mashin.“Um, are you really Mashin?”The boy knelt down and asked with a trembling voice. At this, the Nanomachine attached to his cerebrum realized it had been misunderstood.

When he opened his eyes he found that he had been reborn as an extra in a novel, which he finished reading yesterday. On top of that, he has become a student of the same battle academy, where the main plot will happen. Let's accompany Rio on his journey and find out where it leads us.“i will steal protagonists chances, as for what will happen to main plot if i do so? i don't care!” (Rio)*The book cover doesn't belongs to me if someone wants me to take it down please contact me directly.*(MC is selfish and cares most about himself, rather than following the main story he will follow his own will. and there's no harem too.so, if you like a hero of justice and a plot following type mc with a harem or something then this is not your cup of tea.)

What was originally an ordinary day, suddenly became a historical turning point. Enormous, mysterious Cubes appeared all over the world without warning and as if Judgement Day’s spears, inserted themselves into the blue planet.

From inside the enormous Cubes, endless streams of monsters gushed out alike raging tides, utterly defeating the unguarded armies of each state in the blink of an eye.

In order for humanity to preserve its final embers, the heads of states issued orders of retreat, to no longer attack the Cubes but rather to cling to remote cities, which they turned into self-sufficient survivor bases and around which they built 100-meter-tall Walls of Life!

Many years later, while bearing the heavy weight of history, the first expeditionary force brought back a world changing piece of information. The Cubes possessed exceedingly high intelligence and they regularly transmitted mission instructions to humans nearby. The mission rewards were incredible.

Since then, humans rushed out of the confines of the walls and once more set foot on the wasteland!

- Description from Novelupdates