Crimson Knife treated Ashred and Ripple's injuries when they first arrived in Underhoof, after an encounter with Cinder Trails and various ghouls. To pay the medical fee's the town sends Ashred and Ripple to guard Fluster as they explore the underground tunnels and eventually find Project Endless.
Crimson Knife treats Ripple and Ashred's minor injuries when they return to Underhoof and provides bathing facilities and medical aid when Ripple and Ashred along with Shade, Ivory and Fluster return to Underhoof. She warns Ripple about taking care of himself, threatening to avoid treating his injuries if he doesn't follow her advice.
Crimson Knife is a fast talking and energetic unicorn. She is obsessed with the health of her patients and their cleanliness as well, forcibly giving out baths to her patients. She is also highly professional in regards to her trade and threatened to withold future treatment from Ripple if he didn't follow her medical advice.
Crimson Knife is a skilled physician able to diagnose and fix a number of different injuries. She also has a powerful teleportation spell at her disposal which she uses on her patients, much to their chargin.