When Spinal has armour he can’t use power devour, everything he tries to absorb gets blocked by the armour and he doesn’t get a skull. Conversely, armour can prevent the opponent from removing his curses so this might be an even trade.
I could be wrong but I tried power devouring a shadow move while I had 3 armour and it looked like on the 4th hit I took damage and still didn’t get a skull. Assuming I didn’t just mess up and hit an attack button by mistake, that really sucks.
PS: Spinal curses are super strong against the AI, I suck with spinal but the AI just cant deal with projectiles without meter.