So I don’t really understand this, but I found a wild Metalheart one tile East of Earun. It appeared alongside the regular monsters, though it was much higher rank. It was probably higher level too, because it had many times more health. I reduced it to almost nothing, but then I realized it was impossible to catch! There was no ark stone or arkadion grade present to tap on. I looked it up on the wiki, which said it was “unobtainable”. Is this because it isn’t supposed to be found, or just because it can’t be caught, like I saw?
No proof, sadly. I didn’t think to take a screenshot, hoping that something special might happen if I just K.O. it.
UPDATE: This gets weirder and weirder. Same place, different Arkadion. Still uncatchable.