do you think that it is possible that the fire dragon igneel, iron dragon metalicana, sky dragon grandine has not gome missing, but rather taken a human form?

I'm pretty sure that was because Porlyusica is the Edolas version of Grandine. So the dragons theoretically all have Edo counterparts which may be human. But they are still missing.

This has got me O.O. I'm pretty sure igneel has been shown at least twice since the story started, at least once before timeskip, and once after. ANyways polyushka knew those because gradine spoke to her telepathically, she said so in the episode.

Igneel was shown in few episodes in the anime.And Wendy and the others only thought that.Porlyushka is only the Edolas form of Grandine who ended up in Earthland. Thats why they had the same voice and smell..

I believe that they have been transported to another dimension, like how Natsu and the others went to Edolas, because of that one episode that contained Igneel and Grandine talking in a volcanic environment. I doubt that that is somewhere on earth because if it were so, wouldn't they have beens spotted when they went out to get food and water? Also, Natsu knew the people in Edolas as the same people on Earthland. If they had something different other than their personalities, wouldn't he have said something at that time? I mean, when Lucy and Edolas Lucy were talking about how they were exactly the same except for their personalities, don't you think Natsu or Wendy would have spoken up saying that something was different other than the personalities. But I do agree that it is weird how Polyushka had telepathic connections with Grandine after she had already gone missing. Maybe that was from the other dimension, like I mentioned before, or maybe it was as she was disappearing. I don't really know. But one think I am sure about, is that Mashima Hiro will eventually make an arc about it. I don't know when, but I can promise he will get around to it, because that is how he is. He brings back things that you would have forgotten about and makes you remember them. So just wait a bit, and all will be explained. But for now, we can only speculate.

Spoiler warning all the dragons put their souls in their dragon slayers to stop them from turning into dragons (like acnolgia (cant spell)) and if the world was coming to and end like with face