The Demon Lord Nightrage was once an ordinary agori. He had a chance encounter with a special stone which allowed him to absorb energized protodermis and grow (but he did not know this). By a twist of fate, in the same day he encountered the protodermis entity. It tried to destroy him but he kept absorbing more and more protodermis (and with it came rage and madness) and was eventually twisted into a monstrous being.