imagine if the master found out about rose and how much she meant to the doctor and the master regenerated as billie piper.
whether they regenerated like that to upset the doctor for villainy purposes or bc they don’t understand love and goodness and just want the doctor to love them is up to you
imagine stumbling onto the riordanverse wiki, without any knowledge of the books, and randomly coming across a character. while just glancing over the information about them this is what you see:
so much of season 3 is about grief (the loss of Rose, Martha bringing up losing her cousin in Smith and Jones, Joan being a widow, The Master coming back and the Doctor having deal with the fall out of being the last of their kind again, Sally in Blink)