So would a fallen Jedi like dooku, or anikin potentially be able to use this, since they were trained initially as jedi then "fell" to the darkside? It would be scary to think of what they could do if they knew/could use those powers
If they knew those powers, yes they would be terrible enemies. I don't think Anakin would know the power because he is not a master and it is only allowed to be learned by a few masters. Dooku might know it, but he hasn't shown any use of it. But I don't think either of them know it. If they did know Morichro, they would be terrible foes to face.