Reader insert. What if W.D Gaster didn't just get split between time and space, but actually ended up in your world in an abandoned hospital you called home? Your were a young child he decided to use as experiments to test human determination in said world and breaks physical laws to test human possibility? He knows of the powers you gained from his experiments... all but one, this one allows you to tear realities just enough to teleport into them. Knowing of Undertale you felt bad for the monsters stuck below in their world and wish to help them, but something goes wrong and you end up going to certain AUs and helping them, gaining the attention of some bad skeletons who now desire your power for them-selfish-selfs.

"Now then...how should I take care of... You? You're in my way!"

She didn't live anywhere near Wall Maria, she lived as far away as you could get. She was tucked in nicely in the interior where she was put in expensive dresses and lived behind the huge slab of concrete known as Wall Sina. But that life? That life just wasn't what she wanted. Playing the role as an obedient daughter to a wealthy family, she suppresses her urges to travel beyond the walls in search of answers to why she was forced into living behind these walls. But one miscalculated visit to Wall Maria and a near death encounter, she realizes the power she yields and understands that the best thing for her was to join in on humanity's fight for it's freedom.

Basically, you're a Titan. Your past is unknown and you have special Titan traits! This book will unlock your shadowy background and open up a whole new world for the humans who hide behind their walls. Hey guys! This book is currently being republished! Thank you all for the waiting, I'm happy to be republishing this again! Add me on PSN! (imjustgoose) Thank you for reading this book, hope everyone enjoys!

You had a horrible life, kicked out of your home for no reason. Your father hated you. You were worthless, nothing. "You were my worst mistake, Y/N." He said. You knew his words were true. You were nothing but people told you that you had talent. You could tell pretty bad jokes and sing, but maybe there's someone who does care for you...