
Nightmare acts very aloof and wary around his niece. Starcross has a good sibling relationship with Lux.


However, when she is with Starcross, she is more laid back, cheerful, and loves to tease her younger brother around a lot. Due to being too kind, her bullies took advantage of her easily. Lux has trouble making friends and was very upset when nobody had accepted her. Lux is very shy and introverted, resembling her Uncle Nightmare Sans prior to his corruption. She was made by her parents via love, creating a flame similar to Dream and Nightmare Sans' energy balls.

She has a younger brother called Starcross. Lux is the child of Dream and Cross Sans.
