Elbisrever
Ghoul
I'd say charging is done in the movement phase, it could be affected by things that for example enhance or restrict movement and your models are moving across the board. And there for it is movement. I just looked it up in the BRB, and it says that charge is needs los and no restrictions from interferring units or terrain in order for it to be legal. The only question is perhaps how to line them up if only one Hexwraith was able to see the enemy at the start of the charge phase