Multiple personality disorder, which I found on Wikipedia is officially "dissociative identity disorder", is actually extremely rare. If you want to read the full article, click <-- there.

Basically, what it says for you blog readers, is that DID is characterized by two distinct identities that alternatively control a person's actions, etc. It's about 1-3% of the population of America. It's most likely to happen through trauma, mild to severe.

So. How does this tie in to Jak?

Well, lessee. He's gonna have two identities. By forcing most or all of the plant out of his body at any one time, he's going to have a no-force-ability body, albiet very good slicer. As a plant, he'll have wonderful force skills and be a good pilot. We'll call his plant identity Jak, since that's who Jak is famous to be. And we'll call his other personality Elijak.

So. Elijak is characterized by being somewhat paranoid, yet loyal when needed. He knows he can turn plant, he just doesn't know what happens to him. He calls Jak "the other guy". And can transform into him on command. Vinithi-Be-Gone will not work on him.

Jak, on the other hand, is a lot more bravado-styled, so he's not quite as reliable. But he's still reliable. He knows he can turn back, and knows what happens when he does. He tries to go as long as he can in plant mode, therefore. He calls Elijak the "little guy". He too can transform on command. And Vinithi-Be-Gone will work.