I can only tell you what I (very) vaguely remember of the story of Jinsiek and John.
One of the two, I'll say Jinsiek, was one of the early glyphbearers after time shattered. Everyone was still very unfamiliar with the wind and the glyphbearering, but they knew that if you left the protective radius of Illari stone, you would become a monster. John was Jinsiek's pal. One day, John went out in the wind and didn't return. Jinsiek went out looking for him, and found him, tied him up, and brought him back to the Illari stone, but he had long-since gone mad. Jinsiek kept him tied up and hidden in his basement or some such thing. Jinsiek tried unsuccessfully to 'cure' John, and in desperation, he attempted to use a glyph transfer scroll to give John his glyph. It worked, but John wasn't cured. Instead, John gained the ability to come and go within the Illari stone's radius, but was still monstrous and evil and shit was all fucked up.
DISCLAIMER: I have likely brutally mangled the story / combined two or more stories / made everything up, but this is what I remember from playing lots of Valley 1.