Recently I have been looking into different myths and theories in Pokemon X and one that I'm interested is the "Lava Dome" one (Yeah what a lame one to find interesting while there a bunch of other cools ones, like the missing Chief Editor, the Lumiose City ghost Girl, the Coriway Town train Station, the Strange Souvenir, etc.).
After just randomly passing by two women in Jaune Plaza in Lumiose City I notice the speech bubble from one of them saying how theres a Lava Dome Pokemon in Jaune Plaza. But your there in Jaune Plaza and there isn't any kind of Pokemon around there. Well for starters the "Lava Dome Pokemon" is Heatran a Fire/Steel Minor Legendary from the Sinnoh region. A lot of people believe the Lava Dome one they are talking about is Volcanion, but his classification if the "Steam Pokemon" not "Lava Dome". So from what I've read and seen on YouTube nothing happens if you take a Heatran there (don't have one so I can't experiment myself). But I have come up with a pretty stupid theory in which I would like to hear your opinion on.
Many believe that you'll get Volcanion in the Power Plant after receiving the Key via Mystery Gift event (could happen who knows), but I think that Volcanion and the Heatran mentioned in Jaune Plaza have some sort of connection. My theory is that there will be some kind of event or patch where you will find a Heatran in Jaune Plaza and after fighting/capturing/finding it you'll receive the Key for the Power Plant and the person might ask you to take Heatran to the Magma Plant due to some possible "Lava issues" they might be having in which there you'll get the Key for the Steam plant and fight Volcanion there, who's giving the workers there some issues.
Something simple like that be good but I was thinking that it would be interesting if Heatran and Volcanion were either giving some kind of relationship whether it be that they are Rivals and hate each other or they get can help each other in someway.
As I said it's a stupid theory let me know you thoughts below in the comments.