The idigam are spirits without clear analogs in the physical world. While a cat-spirit is emblematic of a cat, and a hate-spirit cannot be other than hateful, these spirits did not have natures. This should mean death for a spirit, and yet the idigam have been able to thrive. Moreover, they were able to take other spirits (or living creatures) and assume their traits, which made them impossible to contain or kill. The only way to rid Pangaea of them was to imprison them on the moon, in a place devoid of raw material. The idigam therefore entered stasis, unable to mimic anything around them. As they have returned to Earth, however, many idigam have learned to "congeal" themselves, developing true Influences at the cost of some of their inherent instability.
// Wiki Link //