User blog comment:Miskos3/Fairy Tail Chapter 486: The Fourth Guest, Review/@comment-7418318-20160525151848/@comment-7418318-20160528064051

"MBPs are poisonous. Which means, Erik could eat it."

Maybe, maybe not... though I tend toward to maybe not part more.

First of all, while MBP act like a poison in some ways, that's just a a side-effect of their actual workings. They aren't a muscle- or organ-destroying poison, they are particles that destroy magic, so nothing is certain in this regard.

Poison can be anything, organic, non-organic... hell even purely synthetic poisons exist. And then there's also "radition poisoning". With such a wide variety of harmful things being labeled as poison, who can tell what of those Erik is immune to and what not.

But let's give a specific example: Lead.

If you have too much lead in your body, it's called lead poisoning (or at least over here in German speaking countries it's "Bleivergiftung", and the same for any heavy metal getting into the organs and bloodstream). Do you think that Erik would be able to get a lot of lead pumped into his blood and still be fine, just because he's supposedly immune to poisons? I don't think so.

I think Gajeel would be more likely to withstand that. While lead is not iron, they are still both metals. If Natsu is able to eat different kinds of fire, Gajeel might be able to eat different kinds of metals too. I'd have prefered him to be a Metal Dragon Slayer rather than a specific metal to begin with.