Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 13 - 13-26. The Third Auction Day

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?!

I became the childhood friend of the protagonist in a novel. The childhood friend who died from taking drugs.

[Volume 1: Dante Blackthorn]When Anastasia and her sister Marianne are captured and shipped across the seas by pirates, they become commodities to be sold in a distant land. Marianne is taken as a courtesan, while Anastasia barely escapes a terrible fate by pretending to be mute. She is forced into the lowest ring of servants at the royal palace, where she endures a life of servitude and creates beautiful artwork to mask her pain.Despite years passing, Anastasia has never forgotten her sister's promise to return to their family together. However, with her movement restricted and the guards vigilant, escape seems impossible.When Anastasia comes into contact with the Forsaken Prince, her life spirals out of control and she triggers a Crux of incredible proportions. Now battling her own inner demons while navigating the treacherous politics of the royal court, Anastasia must confront the truth about her sister's fate and make a choice that could alter the course of an entire kingdom.[Volume 2: Emily Blackthorn]Princess Emily's life takes a turbulent turn when she is rejected, leaving her heartbroken and her soul at the brink of corruption. In a desperate bid to save herself, she journeys to the West.Enter the Storm Prince, a charismatic archdemon with striking blue eyes, with a saint-like smile. Emily had hoped she'd seen the last of him, but fate has other plans. As if her soul dying isn’t enough, someone wants to steal it!Caught between the suitors and the haunting nightmares that have plagued her since childhood, Emily begins to see Raylen in a new light. The blue-eyed demon may not be the monster she once thought.