The fact that you expose it to a Stone and it turns into a Ghost-type; the implications are a bit unsettling, if one dwells on them for too long, that's all.

As for your Metal Coats - it is a bit of a shame that they're only applicable on so few species, though I have to wonder if our science department would be interested in attempting to change that...?

[bro he will get you so many metal coats if you think you can encase his creatures in steel just saying]