An Exorcist is a curse user as well, though unlike common curse users who use their body as the vessel for curses and focus on a single curse and enhancing its ability. The Exorcist instead seals the curses in their tools or talisman, molding them and changing them to their needs.
Which in turn makes them very weak in direct firepower, but when it comes to sealing and exorcizing evil, they are at the forefront. Making it so that Remira didn't know if she would stand a chance against an Exorcist.
So running away with a limp and broken body, her face bleeding and she could barely hear from her right ear, but staying there was close to a suicide. The only path to survival was escape, which was proven by the fact that she still got shot even after the Exorcist had ordered to stop the shooting.