Complex sentence: But when Valkyrie is attacked by Melancholia, as Craven had let her be by herself for one night, Valkyrie get beaten badly and rushed to the the medical ward at the Sanctuary in Roarhaven, only to find that Doctor Nye is the new doctor.
Split into simpler sentences: But when Valkyrie is attacked by Melancholia, because Craven had let her by herself for one night, Valkyrie gets beaten badly. She is rushed to the the medical ward at the Sanctuary in Roarhaven, only to find that Doctor Nye is the new doctor.