Gildas, Morfran, Mordred, Maelgwn, Sandde, Cynwil, Osfran's Son, Gwyn or Griflet.
These are the characters who can be candidates for reincarnation.
The battle of Camlann or if Salisbury Plain was probably meant to be the example to set the start of the story into a twist.
I am living this here for anyone to read and make their own conclusion.