I never understood how that could have been a debate in the first place. It's obvious to me that DF is yanking your chain and simply disguising himself as a human.
- No other person controlled by Dark Force in the entire series ever acts as nice as Seth does. Very odd behavior.
- Seth is supposedly amazed by the party's strength, but really, he's just as strong if not stronger than any of them. His banter comes off as being really disingenuous and suspicious.
- Seth's true goal for tagging along with you is probably so he can steal the Aero Prism. Use the Talk command after you obtain it but before you step outside of the temple to see what I mean.
- Rune probably doesn't yammer on about Dark Force evolving for no reason. It's strongly implied that DF is using new tactics here.
- The light of the Aero Prism is probably what makes Seth/DF flip out and transform; I don't really think the transformation itself is why he screams.