Lore & Background
The Doctor is a terrifying figure who runs the "Medical Tent," a place that serves less as a hospital and more as a torture chamber. He is responsible for "fixing" the performers, which usually involves grotesque modifications, stitching, and replacing weak flesh with stronger, artificial materials.
He wears a blood-stained surgeon's apron and a mask that looks suspiciously like it's made of stitched skin. He views the performers not as people, but as projects to be continuously improved. His logic is cold, clinical, and completely devoid of empathy.
Day 2 Revelation
In the Day 2 update, a sequence in the Medical Tent reveals that The Doctor's eyes flash a demonic red when he is excited by a new "specimen." It is hinted that he was once a brilliant surgeon in the real world who was driven mad by his obsession with overcoming death, eventually finding his way to the circus where his experiments are unrestricted.
Personality & Role
The Doctor is sadistic, obsessive, and clinically detached. He speaks in medical jargon mixed with threats. He is fascinated by the MC's "fresh" physiology and often muses aloud about how he could "improve" them—removing fear, adding durability, or simply seeing what's inside.
He serves as a major antagonist in the bad endings of both main routes, where the MC often ends up as his latest masterpiece.