MTL - The Little Merman - Chapter 80

She had a lifetime of fake virtue without receiving a virtuous ending. In the next lifetime, she controls fates with the flip of her hand. To the jerk who wasn’t faithful, she’ll draw a premature death talisman for him. For the poisonous step mother, she’ll send a death flower. For the step sister who is two faced, she’ll personally rip off that fake pretty face!

But when she personally offered up her body to her nemesis because of a child who she had no fate with, something unexpected happened. The night of the big wedding, the groom changed and a cold and luxurious man pushed her down. “You can marry whoever you like, but you can only give birth to my children!”

- Description from Novelupdates

I was betrayed in my first life.A cripple, broken and discarded—I died after catching the one I loved in bed with the only person I ever called a friend.That was the start of real torment.When I woke up, it was in another world.A goddess stood before me.She told me I could go back.Back to my world.Back to everything I lost.All I had to do… was play my part.The side character.And I did.I followed the script.Played my role to perfection.They hated me.Mocked me.Used me.Again and again.But I kept going. Because I believed her.Because I wanted to go home.Then one day, I found out.The hard way.It was all a lie.There was no going back.There never was.She used me.Again.Just like everyone else.Thrown away like trash once I outlived my usefulness.That was the day something inside me snapped.And so, I made a vow.I would take everything from her.I would enslave every single heroine she chose.And I would kill the hero she placed all her hopes on.If she wanted to protect this world…Then I would burn it down.But the more I tried, the more things started to change.And then one day—I found one of the heroines.One of the hero's yanderes I had enslaved.She stood there, trembling, a knife in her hand.“You’re not going anywhere,” she whispered, eyes wild.“I won’t let them have you. You belong to me.”...What. The. Fuck. Is. Happening?!

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.

In a world where everyone is undergoing their profession's transition, I've surprisingly awakened to two professions.Moreover, I've also awakened a defiance lifestyle profession.Preserve high-quality items? I'll just synthesize them.Preserve high-quality skills? I'll synthesize those as well.Preserve high-level pets? I'll keep synthesizing. Wait, why is this beast-girl so large after the synthesis?Let's start by synthesizing three “Skeleton Summonings.”Synthesize into—The “Undead Army.”Now, let's synthesize three Dark Wands.Synthesize into—The “Death's Scepter.”In the grand interspecies gaming contest of the universe, can we, humans of the Solar System and Earth, ascend to an even broader stage?......