User blog comment:Wrath022/Chapter 516: The Truth About Enchantment, Review/@comment-30338537-20170102184758/@comment-7418318-20170102204718

I can't be bothered to check, but I'm quite sure that was anime-only filler bullshit.

I don't think that creating anti-bodies would do any good. They were meant to prevent the transformation from happening, not reverse it after the fact.

There's also the potential problem of Belserion having been dead for 400 years, unlike Igneel & Co who entered the bodies of the DS very shortly after losing their souls to Acnologia.