I doubt you'd need the invincibility code. Just get RedHawke's Exile Item Pack. :P
But anyway, I think there was some variable that could be altered with KSE to produce the same effect. Something that never lets a character's VP drop below 1, if I recall. Never tried it myself, but it should be in the character properties section on KSE.
One thing that fools will never understand is that only a weakling lets the darkness control him. A mix of light and darkness is a powerful thing. Volatile, yes, but also unexpected, and thus even more dangerous.