I recently added the Whispering Shade to my party and decided on equipping the Ime Rune to hopefully augment the ability.
Without the rune, my creatures lose Invis at the start of their turn. With the rune, they have a 30% chance to keep invis, but there doesn’t seem to be a point. It appears that no matter what action my creatures take they will lose invis. So why waste a rune spot to keep invis when it gains you nothing?
I then thought that maybe it is for in case you have a disable status like stun? I suppose the invis would stay then, but if the rune is only helpful for those rare situations, then it should proc 100% of the time.