I have a problem with this capacity of the gruagachan/infernalists.
With the external soul, it seems it's not possible to die from injury, it gives unaging...
But nowhere I was able to find an indication about the accumulation of aging points and decrepitude. And decrepitude don't give any physical injury.
It seems that gruagachan can gain decrepitude (and they can fall sick, or have crisis too), and at the score of 5... Couic !
External soul or not.
Well, it wasn't like this in the precedent version of this magical lineage, so I'm surprised. They are already limited by the warping, but it seems that aging is for them a greater threat.
What do you think ?