Also, all the wizards he remembered had a wand to cast spells. Voldemord has been talking about that instrument as if it is a ballast, that does not allow him to open the full potential. Maybe that is also right, but at the same time the artifact is needed for not to lose the aforementioned potential at all. When magic passes through the human it creates a great pressure on it. Ghosts in his previous life were able to withstand it with their strong bodies, while He Xuan’s current species needed some support. Conductor as wand is able to take most of the pressure, leaving just a magic itself to free outside. But without a wand or a different conductor, all that pressure will go directly via the body, gradually destroying it.