I'm not sure but I think that Desann's behaviour at Artus Prime (JKO) isn't part of the programming nor the npc file. If I'm right so the attacking with the force like this is coded in the compiled icarus scripts (*.ibi)
But if you want to have a pure force user with a saber defense so you need either to edit the icarus scripts (sp) or make a new mod and add a new npc class which also need a npc
(just mp)