I recently started reading this story from the first part in th 100 and it is one of the fue that I have read all available ch without switching to another book every few ch

i am not sure if I remember correctly, but if I do, then Fels was a man before he became a skeleton because he tried to create a spell that would revive his dead family. it was in the main books when Bell and his Familia were recovering when the xenos were on the surface and being attacked by the Loki Familia