User blog comment:EvanDude345rv5/Fairy Tail Chapter 358 Review : Magical Barrier Particles/@comment-117.227.52.242-20131103003505/@comment-4829046-20131104033825

Again, "Magic destroying poison damages both body and magic powerMagic destroying poison damages both body and magic power"

^this applies to Cobra, like you said, its not "traditional poisoning". We have NO evidence that Cobra can withstand it.