So I was helping my friend who was playing for his first time
We got up to the mission where you first meet maskeraith.
When he tried the invisibility power his body disappeared and I could
only see accessories, his shield and a few parts of his armor.
IMAGE: http://imgur.com/gallery/2DbNHqy
It remained this way until the next floor
I am guessing its lag related so you may want to check
Can you provide a list of the installed hardware on your PC?