User blog comment:IamJakuhoRaikoben/Chapter 473: Red Lightning, Review./@comment-7418318-20160215134501/@comment-7418318-20160215190918

Further up in the comments Wrath analyzed just that, but it doesn't really matter what they are called, it matters what they do.

In the Tartaros arc we got a pretty detailed description of how, despite their name, they are functioning literally as anti-magical particles that destroy the ethernano around themselves.

And that function is fundementally different from an actual barrier. MBP don't put up a forcefield or enforce any kind of rule, they just literally destroy magic around them and thus shouldn't be able to be affected by magic, they destroy the magic before it can touch them.