Reborn in an Undertale AU as Not a Sans?

A random Undertale fan is killed in a plane crash, and wakes up in a Gray Void as a skeleton. Scared and confused they realize they have similar magic to Ink when they accidently make a flower. After a while they end up creating there own AU, but forget to create a Sans. Not knowing what else to do they take Sans's place in the story under the name Lustic.