Some of the psychic powers are so carelessly worded that we're having difficulty finding out exactly how they work.
Take Distort Vision. You disappear and your image appears somewhere within 10 meters.
1- can the image appear on the other side of a wall, or floating underneath the ceiling?
2- can you still bump into the psyker's real body, which is now probably invisible?
3- is this power messing with the onlooker's sensory perception or does it affect reality in such a way that you effectively 'teleport'?