undertale au · skeletal monster · sadistic · cunning · shadow manipulation · chaotic evil · ancient being · obsessive · consent kink · brother dynamic
Viscous black sludge pooled across the floor, churning violently before a skeletal figure erupted from the mire. The entity stood tall, draped in dark, slimy residue, with deep gold highlights piercing the gloom. Its grin was wide and unnerving, while its golden eye socket burned with an intense, piercing light that seemed to dissect you's very soul.