Born quirkless on a world where everybody got special powers Y/n was threated badly, humillated and attacked by those with powers, growing up without knowing what is Love, Mercy or having someone to care about you she quickly gain a hate towards all humanity, so she run away to a place where nobody would ever find her, Mt. Ebott. legends say that monsters where sealed up there in the past and everybody who climbed was never seeing again, that was the perfect place, not even the strongest heroes or the most dangerous Villains would dare to climb it, so she climb it, once in the top she found a hole, not carring what would happen to her, she jump on it, there was nothing more than the solid ground to stop her fall, Pain was all she felt, alone in the darkness was how she tought she would die until a small voice got her attention, A goat boy run and help her, he brought her to his family wherd they heal her wounds and take care of her, turning her in a member of their family, she didn't trust them at first nut with the time she got used to the love, she loved the underground and the monsters, she manage to learn the power of DETERMINATION, even if she wasn't able to act kind or show her love in the right way, she wanted to help and free them, so she got a plan to gather the seven humans souls, losing her own live in the prosses and her Brother absorbing it, Asriel was able to escape the underground, Taking the body of her Sister to the surface, the same humans that once hated her where atacking the monster that they thought that killed her. Y/n screamed and try to force Asriel body to kill all of them, but he didn't, he didn't want to harm them, so he just stod there until he couldn't more and return to the underground where he died, Y/n found herself trapped on a place where there was nothing except for herself and another being, Y/n didn't understand that monster he speak with his hands, with the years she saw how more and more humans fall to underground as she learned how to understand her new friend, That was until they fall, Two Humans, A girl and A boy, the boy slighlty older that the girl, they where different as the others souls they just like Y/n got DETERMINATION, Y/n Watch them closely following them as a ghostly companion, They fall on a genocide route, by the end of it Y/n was already in control lf their boddies, she was facing the comedian skeleton, she hated this fight but at the same time she loved it, She hated that the damn comedian keep dodging every attack and Killing her at every moment, and she loved how alive she felt, she could fell the pain, the tired body of frisk, the dessesperations to kill Sans, and the joy when she finally did it, But unfortunatelly she understimate the DETERMINATION of the humans, whe her soul was free and she met them, they reset everything, she got trapped again in the void as the humans go with a pacifist route freeing the monsters, Thanks to the help of her friend Gaster Y/n was able to get her body back, but she was alone there was nobody in the underground, That until one day saw Frisk again, she came back to get flowey, She stay on the shadows watching them as they leave, but when Frisk was getting out she stopped and turned around looking at where Y/n was hidding, Frisk offer Y/n taking her out of the underground and go with her to live in the surface, Y/n had confused feelings on that moment she didn't knew if take the offer, leave them or kill them at that moment, Frisk was smiling at her and flowey look at her as if he expected her to go with them, Y/n was going to turn back to the ruins when she felt Gaster's pressence there, he grab her and push her towards Frisk, Frisk take both Y/n and Flowey with her, Toriel and Asgore couldn't belive that Y/n was alive they hug her as if it was all a dream and Y/n would just disapear, they ask her thousands of questions about where she was or how she retunr to life, she answer with a simple "I don't remember much" Frisk then explain them who Flowey was, The Dreemurr family was reunited again, this time with two new members Frisk and Kris, Thanks to Alphys' help Flowey return to be Asriel, Y/n continue killing, mostly humans but some times she Kill some monsters doing this on the night, Avoiding the heroes, But she can't keep avoiding them forever