User blog comment:IamJakuhoRaikoben/Chapter 473: Red Lightning, Review./@comment-1776824-20160216185112/@comment-2214433-20160216212715

I'd say it's more simple.

Magical barrier is made of... *wait for it * ... magical barrier particles. Just that the particles themselves act as a poison if inside one's body. Not like anyone can eat Freed's magic. Except for Natsu maybe