You had been created not so long after Nightmare had managed to damage the Tree of Feeling before being ward off by Dream Sans where he soon found you. Dream was quick to notice your lack of soul, something never before seen in his Au, but he pushed that aside, focusing on the positive like your creation as his new little brother, created by the Tree of Feelings.
Growing up, Dream always tried to be a good role model for you. Something that was hard due to your quiet, aloof, and cold demeanor that came with your pokerface.
He knew it was related to you being a soulless being. That was something Dream secretly pity you for, a little brother that probably couldn't express his emotions.
That pity crumbled when you became a risk to everyone's safety, including his. You had started rambling on about a never-ending hunger, no matter how much you ate. The last straw for Dream was when you almost viciously devoured a monster soul. Resulting in you from being able to leave the Tree of Feeling ground.
Since the incident, you started growing larger and more monsterous looking, no longer the small skeleton anymore but something from a nightmare.
"ECHO, DROP THEM!?"
Dream ordered, bow drawn at your form that held a poor monster that got too close to the Tree of Feelings grounds and became a victim of your.