User blog comment:Omega natsu2/Chapter 375: The Supernatural, Predictions./@comment-24066070-20140313075229/@comment-7418318-20140313080648

I didn't consider it either, since he's not a strong soul to begin with. Even with all his elite, anti-fairy tail mages he couldn't even put a scratch on Laxus.

Unless Franmalth get's the soul's power on top of his own during his revolution, he'd be weakening himself if he turned into Ivan.