Devil's Son-in-Law - Chapter 872: Ice and Fire

Aomori, who has a monster-fighting system, came to the world of One-Punch Man and gained the ability to enter various instances.

Therefore, “Founder of the Hero Association”, “NO. “And other titles fell on him one after another.

Comprehensive flow, the main world One Punch Man.

Completed dungeons so far: Pokémon – Demon Slayer – Sword – Pokémon – Digimon – Spell Return – Yokai Comprehensive World (Girls that Noragami Inuyasha can see, etc.) – Pokémon – One Piece-re0-Dragon Ball wait.

- Description from novelbuddy

There are Humans. There are Elves. There are Dwarves. There are Orcs. And then there are Demons, and the Demon King.In a world where warriors wield elemental fury, assassins bend shadows, and mages rewrite the laws of reality with a thought… one boy awakens the weakest and funniest ability of all.[Muscle Genesis]… the power to grow and control muscle.The f*ck? No sword aura, no magic affinity, no flashy technique, just raw, brutal power.Born in the wild slums of Arcanum Nexus, orphaned, starving, and forgotten by the system, Kairo Vale has one goal: survive long enough to rise above it all.When his chance finally comes in the form of the prestigious Nexus Academy Entrance Tournament, the world expects him to fail, just another Unranked slum bastard with a useless ability.But the thing about muscles is that… they grow.And so does his pain tolerance, and his strength, and his will to endure.Thrown into trials designed to break him, teamed with nobles who want him gone, and hunted by powers that fear what he might become, Kairo fights back the only way he knows how: one rep, one punch, one brutal threshold at a time.Because in this world, power is everything.And he’s going to build his from the ground up.If they won’t give him a place in their world, he’ll carve one with his fists.

Takahiro Nao, a 25-year-old burdened by crushing debt and driven solely by his love for his struggling family, meets a tragic end—until a mysterious Goddess of Benevolence offers him a second chance: reincarnated in another world, and his efforts there will provide for his family back on Earth. Awakening in the body of Naoki von Blackmore, a disgraced “Failed Hero,” Nao is thrust into a realm of sword and magic, monsters, and war, tasked with the impossible mission of defeating the Demon King. With newfound powers, a shadowy past, and the weight of two worlds on his shoulders, he must battle not only relentless enemies but fate itself. Blending emotional depth, thrilling action, moments of humor, and a spark of romance, this gripping isekai adventure asks: how far would you go—and what would you sacrifice—for the people you love?

Eight hundred years ago, Xie Lian was the Crown Prince of the Xian Le kingdom. He was beloved by his citizens and was considered the darling of the world. He ascended to the Heavens at a young age; however, due to unfortunate circumstances, was quickly banished back to the mortal realm. Years later, he ascends again–only to be banished again a few minutes after his ascension.

Now, eight hundred years later, Xie Lian ascends to the Heavens for the third time as the laughing stock among all three realms. On his first task as a god thrice ascended, he meets a mysterious demon who rules the ghosts and terrifies the Heavens, yet, unbeknownst to Xie Lian, this demon king has been paying attention to him for a very, very long time.

- Description from Novelupdates