This guy is actually quite easy if you have insanity and are able to erode away his will during conversation. All you have to do is use your insanity force power and then just wail upon him until he goes down. Yes he will get back up but keep trying to explain how Kreia hates him and wants him to die and he will continually weaken until he has no more willpower left to fight you after he's taken down.
Submitted By: Chris
Pillar Peek a Boo
For Darth Sion, "simply" run behind the pillars in the room and use throw lightsaber, and if low on health, heal. There are four battles with this stubborn foe but you should find it fairly simple to defeat him, especially if you can manage to lower his will.
